feat: add is_subagent flag to agents, fix all lint/type/test issues

- Add is_subagent checkbox to agent editor; subagents are hidden from Chat Settings
- Add is_subagent field to AgentDefinition type, TOML serialization, and API route
- Filter subagents from ModelSelector agent list
- Fix all biome lint/format errors across codebase (useLiteralKeys, noNonNullAssertion, noExplicitAny, formatting, import sorting)
- Fix svelte-check errors (type narrowing in SkillsBrowser, ToolPermissions, SidebarPanel)
- Fix a11y warnings in App.svelte (label-control associations)
- Fix test mocks missing BackgroundShellStore, BackgroundTranscriptStore, createWebSearchTool, createYoutubeTranscribeTool
- Update stale 409 test to match current message-queuing behavior
- Exclude packaging/ and release/ dirs from biome to avoid linting stale build artifacts

31 files changed, 368 insertions, 231 deletions

diff --git a/packages/api/src/agent-manager.ts b/packages/api/src/agent-manager.ts
index 3789b68..74995b2 100644
--- a/packages/api/src/agent-manager.ts
+++ b/packages/api/src/agent-manager.ts
@@ -4,6 +4,8 @@ import {
 	type AgentSkillMapping,
 	type AgentStatus,
 	appendMessage,
+	BackgroundShellStore,
+	BackgroundTranscriptStore,
 	type ClaudeAccount,
 	configToRuleset,
 	createConfigWatcher,
@@ -11,8 +13,6 @@ import {
 	createReadFileTool,
 	createRetrieveTool,
 	createRunShellTool,
-	BackgroundShellStore,
-	BackgroundTranscriptStore,
 	createSkillsWatcher,
 	createSummonTool,
 	createTaskListTool,
@@ -298,13 +298,15 @@ export class AgentManager {
 		const effectiveKeyId = keyId ?? tabAgent.keyId;
 		const effectiveModelId = modelId ?? tabAgent.modelId;
 
-		// Read tool permission settings from DB (default: read=allow, edit=ask, bash=ask, summon=ask)
+		// Read tool permission settings from DB (default: read=allow, edit=ask, bash=ask, summon=ask, web=ask, youtube=ask)
 		const permRead = getSetting("perm_read") !== "ask";
 		const permEdit = getSetting("perm_edit") === "allow";
 		const permBash = getSetting("perm_bash") === "allow";
 		const permSummon = getSetting("perm_summon") === "allow";
+		const permWebSearch = getSetting("perm_web_search") === "allow";
+		const permYoutubeTranscribe = getSetting("perm_youtube_transcribe") === "allow";
 		const sysPrompt = getSetting("system_prompt") ?? "";
-		const permKey = `${permRead}:${permEdit}:${permBash}:${permSummon}:${sysPrompt}`;
+		const permKey = `${permRead}:${permEdit}:${permBash}:${permSummon}:${permWebSearch}:${permYoutubeTranscribe}:${sysPrompt}`;
 
 		// If the override differs or permissions changed, invalidate the cached agent
 		if (
@@ -358,13 +360,19 @@ export class AgentManager {
 					toolEntries.push({ name: "write_file", tool: createWriteFileTool(workingDirectory) });
 				}
 				if (allowed.has("run_shell")) {
-					toolEntries.push({ name: "run_shell", tool: createRunShellTool(workingDirectory, tabAgent.shellStore) });
+					toolEntries.push({
+						name: "run_shell",
+						tool: createRunShellTool(workingDirectory, tabAgent.shellStore),
+					});
 				}
 				if (allowed.has("web_search")) {
 					toolEntries.push({ name: "web_search", tool: createWebSearchTool() });
 				}
 				if (allowed.has("youtube_transcribe")) {
-					toolEntries.push({ name: "youtube_transcribe", tool: createYoutubeTranscribeTool(tabAgent.transcriptStore) });
+					toolEntries.push({
+						name: "youtube_transcribe",
+						tool: createYoutubeTranscribeTool(tabAgent.transcriptStore),
+					});
 				}
 				if (allowed.has("todo")) {
 					toolEntries.push({ name: "todo", tool: createTaskListTool(tabAgent.taskList) });
@@ -408,10 +416,20 @@ export class AgentManager {
 					toolEntries.push({ name: "write_file", tool: createWriteFileTool(workingDirectory) });
 				}
 				if (permBash) {
-					toolEntries.push({ name: "run_shell", tool: createRunShellTool(workingDirectory, tabAgent.shellStore) });
+					toolEntries.push({
+						name: "run_shell",
+						tool: createRunShellTool(workingDirectory, tabAgent.shellStore),
+					});
+				}
+				if (permWebSearch) {
+					toolEntries.push({ name: "web_search", tool: createWebSearchTool() });
+				}
+				if (permYoutubeTranscribe) {
+					toolEntries.push({
+						name: "youtube_transcribe",
+						tool: createYoutubeTranscribeTool(tabAgent.transcriptStore),
+					});
 				}
-				toolEntries.push({ name: "web_search", tool: createWebSearchTool() });
-				toolEntries.push({ name: "youtube_transcribe", tool: createYoutubeTranscribeTool(tabAgent.transcriptStore) });
 				toolEntries.push({ name: "todo", tool: createTaskListTool(tabAgent.taskList) });
 				if (permSummon) {
 					// Capture parent's allowed tool names for child permission enforcement
@@ -544,25 +562,25 @@ export class AgentManager {
 				tabAgent.modelId = null;
 			}
 
-		const customSystemPrompt = getSetting("system_prompt") || undefined;
-		tabAgent.agent = new Agent(
-			{
-				model,
-				apiKey,
-				baseURL,
-				systemPrompt: buildSystemPrompt(toolNames, customSystemPrompt),
-				tools,
-				workingDirectory,
-				permissionChecker: this.permissionManager ?? undefined,
-				ruleset,
-				provider,
-				...(claudeCredentials ? { claudeCredentials } : {}),
-			},
-			{
-				dequeueMessages: () => this.dequeueMessages(tabId),
-				waitForQueuedMessage: () => this.waitForQueuedMessage(tabId),
-			},
-		);
+			const customSystemPrompt = getSetting("system_prompt") || undefined;
+			tabAgent.agent = new Agent(
+				{
+					model,
+					apiKey,
+					baseURL,
+					systemPrompt: buildSystemPrompt(toolNames, customSystemPrompt),
+					tools,
+					workingDirectory,
+					permissionChecker: this.permissionManager ?? undefined,
+					ruleset,
+					provider,
+					...(claudeCredentials ? { claudeCredentials } : {}),
+				},
+				{
+					dequeueMessages: () => this.dequeueMessages(tabId),
+					waitForQueuedMessage: () => this.waitForQueuedMessage(tabId),
+				},
+			);
 		}
 		return tabAgent.agent;
 	}
@@ -672,7 +690,7 @@ export class AgentManager {
 		// Intersect requested tools with parent's allowed tools to prevent privilege escalation
 		let childTools = options.tools;
 		if (options.parentAllowedTools) {
-			childTools = options.tools.filter((t) => options.parentAllowedTools!.has(t));
+			childTools = options.tools.filter((t) => options.parentAllowedTools?.has(t));
 		}
 
 		// Create the tab agent entry with overrides
@@ -931,10 +949,7 @@ export class AgentManager {
 		const messages = [...tabAgent.messageQueue];
 		tabAgent.messageQueue = [];
 		if (messages.length > 0) {
-			this.emit(
-				{ type: "message-consumed", tabId, messageIds: messages.map((m) => m.id) },
-				tabId,
-			);
+			this.emit({ type: "message-consumed", tabId, messageIds: messages.map((m) => m.id) }, tabId);
 		}
 		return messages;
 	}
@@ -951,7 +966,7 @@ export class AgentManager {
 		});
 		const cancel = () => {
 			if (listener) {
-				tabAgent.queueListeners = tabAgent.queueListeners.filter(l => l !== listener);
+				tabAgent.queueListeners = tabAgent.queueListeners.filter((l) => l !== listener);
 				listener = null;
 			}
 		};
diff --git a/packages/api/src/app.ts b/packages/api/src/app.ts
index 53cfb6c..9ccc911 100644
--- a/packages/api/src/app.ts
+++ b/packages/api/src/app.ts
@@ -63,7 +63,8 @@ app.post("/chat", async (c) => {
 
 	const keyId = typeof body.keyId === "string" ? body.keyId : undefined;
 	const modelId = typeof body.modelId === "string" ? body.modelId : undefined;
-	const workingDirectory = typeof body.workingDirectory === "string" ? body.workingDirectory : undefined;
+	const workingDirectory =
+		typeof body.workingDirectory === "string" ? body.workingDirectory : undefined;
 	const validEfforts = ["none", "low", "medium", "high", "max"];
 	const reasoningEffort =
 		typeof body.reasoningEffort === "string" && validEfforts.includes(body.reasoningEffort)
@@ -71,7 +72,9 @@ app.post("/chat", async (c) => {
 			: undefined;
 
 	// Non-blocking — let the agent run in the background
-	agentManager.processMessage(tabId, message, keyId, modelId, reasoningEffort, workingDirectory).catch(console.error);
+	agentManager
+		.processMessage(tabId, message, keyId, modelId, reasoningEffort, workingDirectory)
+		.catch(console.error);
 
 	return c.json({ status: "ok" });
 });
diff --git a/packages/api/src/routes/agents.ts b/packages/api/src/routes/agents.ts
index 42339bf..d3ca23f 100644
--- a/packages/api/src/routes/agents.ts
+++ b/packages/api/src/routes/agents.ts
@@ -56,6 +56,7 @@ agentsRoutes.post("/", async (c) => {
 			scope: body.scope,
 			slug: body.slug,
 			...(body.cwd ? { cwd: body.cwd } : {}),
+			...(body.is_subagent ? { is_subagent: true } : {}),
 		};
 		saveAgent(agent);
 		return c.json({ ok: true, agent });
diff --git a/packages/api/src/routes/models.ts b/packages/api/src/routes/models.ts
index d6b82c2..b250263 100644
--- a/packages/api/src/routes/models.ts
+++ b/packages/api/src/routes/models.ts
@@ -112,7 +112,7 @@ modelsRoutes.get("/available", async (c) => {
 		});
 	}
 
-	const apiKeyValue = resolveApiKey(keyId!);
+	const apiKeyValue = resolveApiKey(keyId);
 	if (!apiKeyValue) {
 		return c.json({ error: `no API key found for ${keyId}` }, 500);
 	}
@@ -420,10 +420,7 @@ modelsRoutes.post("/add-key", async (c) => {
 
 	// Validate provider
 	if (!VALID_PROVIDERS.includes(body.provider as SupportedProvider)) {
-		return c.json(
-			{ error: `provider must be one of: ${VALID_PROVIDERS.join(", ")}` },
-			400,
-		);
+		return c.json({ error: `provider must be one of: ${VALID_PROVIDERS.join(", ")}` }, 400);
 	}
 	const provider = body.provider as SupportedProvider;
 	const base_url = PROVIDER_BASE_URLS[provider];
@@ -452,7 +449,7 @@ modelsRoutes.post("/add-key", async (c) => {
 	newBlock += "\n";
 
 	// Insert before the # ─── Permissions section if it exists, otherwise at end
-	const permissionsMarker = /\n# [─\-]+ Permissions/;
+	const permissionsMarker = /\n# [─-]+ Permissions/;
 	let newContent: string;
 	const permMatch = permissionsMarker.exec(tomlContent);
 	if (permMatch) {
@@ -509,7 +506,8 @@ modelsRoutes.post("/remove-key", async (c) => {
 		return c.json({ error: `key "${id}" not found in dispatch.toml` }, 404);
 	}
 
-	const newContent = tomlContent.slice(0, match.index) + tomlContent.slice(match.index + match[0].length);
+	const newContent =
+		tomlContent.slice(0, match.index) + tomlContent.slice(match.index + match[0].length);
 
 	try {
 		writeFileSync(tomlPath, newContent, "utf-8");
diff --git a/packages/api/tests/agent-manager.test.ts b/packages/api/tests/agent-manager.test.ts
index f8e5e12..b426c4e 100644
--- a/packages/api/tests/agent-manager.test.ts
+++ b/packages/api/tests/agent-manager.test.ts
@@ -169,6 +169,38 @@ vi.mock("@dispatch/core", () => ({
 		return null;
 	},
 	appendMessage() {},
+	BackgroundShellStore: class MockBackgroundShellStore {
+		has() {
+			return false;
+		}
+		getResult() {
+			return Promise.resolve({ status: "error", error: "not found" });
+		}
+	},
+	BackgroundTranscriptStore: class MockBackgroundTranscriptStore {
+		has() {
+			return false;
+		}
+		getResult() {
+			return Promise.resolve({ status: "error", error: "not found" });
+		}
+	},
+	createWebSearchTool() {
+		return {
+			name: "web_search",
+			description: "web search",
+			parameters: { _type: "z.ZodObject", shape: {} },
+			execute: async () => "mock",
+		};
+	},
+	createYoutubeTranscribeTool() {
+		return {
+			name: "youtube_transcribe",
+			description: "youtube transcribe",
+			parameters: { _type: "z.ZodObject", shape: {} },
+			execute: async () => "mock",
+		};
+	},
 }));
 
 // Import after mock is defined (Vitest hoists vi.mock automatically)
diff --git a/packages/api/tests/routes.test.ts b/packages/api/tests/routes.test.ts
index 05f8358..c3c7eaa 100644
--- a/packages/api/tests/routes.test.ts
+++ b/packages/api/tests/routes.test.ts
@@ -170,6 +170,38 @@ vi.mock("@dispatch/core", () => ({
 		return null;
 	},
 	appendMessage() {},
+	BackgroundShellStore: class MockBackgroundShellStore {
+		has() {
+			return false;
+		}
+		getResult() {
+			return Promise.resolve({ status: "error", error: "not found" });
+		}
+	},
+	BackgroundTranscriptStore: class MockBackgroundTranscriptStore {
+		has() {
+			return false;
+		}
+		getResult() {
+			return Promise.resolve({ status: "error", error: "not found" });
+		}
+	},
+	createWebSearchTool() {
+		return {
+			name: "web_search",
+			description: "web search",
+			parameters: { _type: "z.ZodObject", shape: {} },
+			execute: async () => "mock",
+		};
+	},
+	createYoutubeTranscribeTool() {
+		return {
+			name: "youtube_transcribe",
+			description: "youtube transcribe",
+			parameters: { _type: "z.ZodObject", shape: {} },
+			execute: async () => "mock",
+		};
+	},
 }));
 
 const { app } = await import("../src/app.js");
@@ -241,7 +273,7 @@ describe("POST /chat", () => {
 		expect(res.status).toBe(400);
 	});
 
-	it("returns 409 when agent is already running", async () => {
+	it("queues message when agent is already running", async () => {
 		// Start a message (non-blocking)
 		await app.request("/chat", {
 			method: "POST",
@@ -252,12 +284,15 @@ describe("POST /chat", () => {
 		// Small delay to let the async generator start and emit "running" status
 		await new Promise<void>((r) => setTimeout(r, 20));
 
-		// Immediately send a second — agent should be running
+		// Send a second — agent should queue it
 		const res = await app.request("/chat", {
 			method: "POST",
 			headers: { "Content-Type": "application/json" },
 			body: JSON.stringify({ tabId: "tab-2", message: "second message" }),
 		});
-		expect(res.status).toBe(409);
+		expect(res.status).toBe(200);
+		const body = await res.json();
+		expect(body.status).toBe("queued");
+		expect(typeof body.messageId).toBe("string");
 	});
 });
diff --git a/packages/core/src/agent/agent.ts b/packages/core/src/agent/agent.ts
index 64a602b..6f1a5a4 100644
--- a/packages/core/src/agent/agent.ts
+++ b/packages/core/src/agent/agent.ts
@@ -188,12 +188,12 @@ export class Agent {
 		}
 
 		try {
-		const execPromise = tool.execute(tc.arguments, {
-			onOutput: (data: string, stream: "stdout" | "stderr") => {
-				shellOutputQueue.push({ data, stream });
-			},
-			queueCallbacks: this.queueCallbacks,
-		});
+			const execPromise = tool.execute(tc.arguments, {
+				onOutput: (data: string, stream: "stdout" | "stderr") => {
+					shellOutputQueue.push({ data, stream });
+				},
+				queueCallbacks: this.queueCallbacks,
+			});
 
 			const rawResult = await execPromise;
 			const resultStr = typeof rawResult === "string" ? rawResult : JSON.stringify(rawResult);
@@ -320,9 +320,7 @@ export class Agent {
 					}
 				} catch (streamErr) {
 					const errMsg = streamErr instanceof Error ? streamErr.message : String(streamErr);
-					const unavailMatch = errMsg.match(
-						/tried to call unavailable tool '([^']+)'/i,
-					);
+					const unavailMatch = errMsg.match(/tried to call unavailable tool '([^']+)'/i);
 					if (!unavailMatch) throw streamErr;
 
 					// Model tried to call an unavailable tool.
@@ -391,8 +389,8 @@ export class Agent {
 					let toolResult: ToolResult | undefined;
 					while (toolResult === undefined) {
 						if (shellOutputQueue.length > 0) {
-							const item = shellOutputQueue.shift()!;
-							yield { type: "shell-output", data: item.data, stream: item.stream };
+							const item = shellOutputQueue.shift();
+							if (item) yield { type: "shell-output", data: item.data, stream: item.stream };
 							continue;
 						}
 						const raceResult = await Promise.race([
@@ -406,30 +404,28 @@ export class Agent {
 						}
 					}
 
-				// Drain any remaining shell output emitted before we read the result
-				while (shellOutputQueue.length > 0) {
-					const item = shellOutputQueue.shift()!;
-					yield { type: "shell-output", data: item.data, stream: item.stream };
-				}
+					// Drain any remaining shell output emitted before we read the result
+					while (shellOutputQueue.length > 0) {
+						const item = shellOutputQueue.shift();
+						if (item) yield { type: "shell-output", data: item.data, stream: item.stream };
+					}
 
-				// Check for queued user messages and append them to the tool result
-				let finalToolResult = toolResult;
-				if (this.queueCallbacks) {
-					const queuedMsgs = this.queueCallbacks.dequeueMessages();
-					if (queuedMsgs.length > 0) {
-						const userMessages = queuedMsgs
-							.map((m) => m.message)
-							.join("\n---\n");
-						finalToolResult = {
-							...toolResult,
-							result: `${toolResult.result}\n\n[USER INTERRUPT]\nThe user has sent you message(s) while you were working. You MUST address these before continuing with your current task:\n\n${userMessages}`,
-						};
+					// Check for queued user messages and append them to the tool result
+					let finalToolResult = toolResult;
+					if (this.queueCallbacks) {
+						const queuedMsgs = this.queueCallbacks.dequeueMessages();
+						if (queuedMsgs.length > 0) {
+							const userMessages = queuedMsgs.map((m) => m.message).join("\n---\n");
+							finalToolResult = {
+								...toolResult,
+								result: `${toolResult.result}\n\n[USER INTERRUPT]\nThe user has sent you message(s) while you were working. You MUST address these before continuing with your current task:\n\n${userMessages}`,
+							};
+						}
 					}
-				}
 
-				stepToolResults.push(finalToolResult);
-				allToolResults.push(finalToolResult);
-				yield { type: "tool-result", toolResult: finalToolResult };
+					stepToolResults.push(finalToolResult);
+					allToolResults.push(finalToolResult);
+					yield { type: "tool-result", toolResult: finalToolResult };
 				}
 
 				// Add tool results back to step messages so LLM can see them
@@ -451,29 +447,29 @@ export class Agent {
 				}
 			}
 
-		const assistantMessage: ChatMessage = {
-			role: "assistant",
-			content: finalText,
-			toolCalls: allToolCalls.length > 0 ? allToolCalls : undefined,
-			toolResults: allToolResults.length > 0 ? allToolResults : undefined,
-		};
-		this.messages.push(assistantMessage);
-
-		// Drain any remaining queued messages that arrived after the last tool call
-		if (this.queueCallbacks) {
-			const remaining = this.queueCallbacks.dequeueMessages();
-			if (remaining.length > 0) {
-				// These messages arrived too late to be injected into a tool result.
-				// Append them as a user message to the conversation so they're not lost.
-				const userMessages = remaining.map(m => m.message).join("\n---\n");
-				this.messages.push({
-					role: "user",
-					content: userMessages,
-				});
+			const assistantMessage: ChatMessage = {
+				role: "assistant",
+				content: finalText,
+				toolCalls: allToolCalls.length > 0 ? allToolCalls : undefined,
+				toolResults: allToolResults.length > 0 ? allToolResults : undefined,
+			};
+			this.messages.push(assistantMessage);
+
+			// Drain any remaining queued messages that arrived after the last tool call
+			if (this.queueCallbacks) {
+				const remaining = this.queueCallbacks.dequeueMessages();
+				if (remaining.length > 0) {
+					// These messages arrived too late to be injected into a tool result.
+					// Append them as a user message to the conversation so they're not lost.
+					const userMessages = remaining.map((m) => m.message).join("\n---\n");
+					this.messages.push({
+						role: "user",
+						content: userMessages,
+					});
+				}
 			}
-		}
 
-		yield { type: "done", message: assistantMessage };
+			yield { type: "done", message: assistantMessage };
 		} catch (err) {
 			const errorMsg = formatError(err, this.config);
 			yield { type: "error", error: errorMsg };
diff --git a/packages/core/src/agents/loader.ts b/packages/core/src/agents/loader.ts
index ec29983..cf84381 100644
--- a/packages/core/src/agents/loader.ts
+++ b/packages/core/src/agents/loader.ts
@@ -112,6 +112,10 @@ export function saveAgent(agent: AgentDefinition): void {
 		tomlContent.cwd = agent.cwd;
 	}
 
+	if (agent.is_subagent) {
+		tomlContent.is_subagent = true;
+	}
+
 	// smol-toml handles [[models]] array-of-tables
 	if (agent.models.length > 0) {
 		tomlContent.models = agent.models.map((m) => ({
@@ -202,6 +206,7 @@ function loadAgentsFromDir(dir: string, scope: string): AgentDefinition[] {
 				scope,
 				slug,
 				...(typeof parsed.cwd === "string" && parsed.cwd ? { cwd: parsed.cwd } : {}),
+				...(parsed.is_subagent === true ? { is_subagent: true } : {}),
 			});
 		} catch {
 			// Skip unparseable files
diff --git a/packages/core/src/config/schema.ts b/packages/core/src/config/schema.ts
index ef10b65..a459a4d 100644
--- a/packages/core/src/config/schema.ts
+++ b/packages/core/src/config/schema.ts
@@ -66,37 +66,37 @@ function validateKey(raw: unknown, path: string, errors: ConfigError[]): KeyDefi
 		errors.push({ path, message: "must be an object" });
 		return null;
 	}
-	if (typeof raw["id"] !== "string") {
+	if (typeof raw.id !== "string") {
 		errors.push({ path: `${path}.id`, message: "must be a string" });
 		return null;
 	}
-	if (typeof raw["provider"] !== "string") {
+	if (typeof raw.provider !== "string") {
 		errors.push({ path: `${path}.provider`, message: "must be a string" });
 		return null;
 	}
-	if (typeof raw["base_url"] !== "string") {
+	if (typeof raw.base_url !== "string") {
 		errors.push({ path: `${path}.base_url`, message: "must be a string" });
 		return null;
 	}
 
 	// "anthropic" provider uses credentials_file instead of env
-	if (raw["provider"] === "anthropic") {
+	if (raw.provider === "anthropic") {
 		return {
-			id: raw["id"] as string,
-			provider: raw["provider"] as string,
-			base_url: raw["base_url"] as string,
-			...(typeof raw["credentials_file"] === "string"
-				? ({ credentials_file: raw["credentials_file"] } as Pick<KeyDefinition, "credentials_file">)
+			id: raw.id as string,
+			provider: raw.provider as string,
+			base_url: raw.base_url as string,
+			...(typeof raw.credentials_file === "string"
+				? ({ credentials_file: raw.credentials_file } as Pick<KeyDefinition, "credentials_file">)
 				: {}),
 		};
 	}
 
 	// Other providers: env is optional (keys can be stored in DB)
 	return {
-		id: raw["id"] as string,
-		provider: raw["provider"] as string,
-		base_url: raw["base_url"] as string,
-		...(typeof raw["env"] === "string" ? { env: raw["env"] } : {}),
+		id: raw.id as string,
+		provider: raw.provider as string,
+		base_url: raw.base_url as string,
+		...(typeof raw.env === "string" ? { env: raw.env } : {}),
 	};
 }
 
@@ -109,17 +109,17 @@ export function validateConfig(raw: unknown): { config: DispatchConfig; errors:
 	}
 
 	// permissions (required, but can be empty)
-	const permissions = validatePermissions(raw["permissions"] ?? {}, "permissions", errors);
+	const permissions = validatePermissions(raw.permissions ?? {}, "permissions", errors);
 
 	// keys (optional)
 	let keys: KeyDefinition[] | undefined;
-	if (raw["keys"] !== undefined) {
-		if (!Array.isArray(raw["keys"])) {
+	if (raw.keys !== undefined) {
+		if (!Array.isArray(raw.keys)) {
 			errors.push({ path: "keys", message: "must be an array" });
 		} else {
 			keys = [];
-			for (let i = 0; i < raw["keys"].length; i++) {
-				const key = validateKey(raw["keys"][i], `keys[${i}]`, errors);
+			for (let i = 0; i < raw.keys.length; i++) {
+				const key = validateKey(raw.keys[i], `keys[${i}]`, errors);
 				if (key) keys.push(key);
 			}
 		}
diff --git a/packages/core/src/index.ts b/packages/core/src/index.ts
index 8d5db16..1e55425 100644
--- a/packages/core/src/index.ts
+++ b/packages/core/src/index.ts
@@ -57,6 +57,9 @@ export { createSummonTool, type SummonCallbacks } from "./tools/summon.js";
 export { createTaskListTool, TaskList } from "./tools/task-list.js";
 export { createWebSearchTool } from "./tools/web-search.js";
 export { createWriteFileTool } from "./tools/write-file.js";
-export { BackgroundTranscriptStore, createYoutubeTranscribeTool } from "./tools/youtube-transcribe.js";
+export {
+	BackgroundTranscriptStore,
+	createYoutubeTranscribeTool,
+} from "./tools/youtube-transcribe.js";
 // Types & Permissions
 export * from "./types/index.js";
diff --git a/packages/core/src/skills/parser.ts b/packages/core/src/skills/parser.ts
index 289073f..bd1205e 100644
--- a/packages/core/src/skills/parser.ts
+++ b/packages/core/src/skills/parser.ts
@@ -30,16 +30,14 @@ export function parseSkillFile(
 			try {
 				const frontmatter = parse(tomlSource);
 
-				if (typeof frontmatter["name"] === "string") {
-					name = frontmatter["name"];
+				if (typeof frontmatter.name === "string") {
+					name = frontmatter.name;
 				}
-				if (typeof frontmatter["description"] === "string") {
-					description = frontmatter["description"];
+				if (typeof frontmatter.description === "string") {
+					description = frontmatter.description;
 				}
-				if (Array.isArray(frontmatter["tags"])) {
-					tags = (frontmatter["tags"] as unknown[]).filter(
-						(t): t is string => typeof t === "string",
-					);
+				if (Array.isArray(frontmatter.tags)) {
+					tags = (frontmatter.tags as unknown[]).filter((t): t is string => typeof t === "string");
 				}
 			} catch {
 				// Malformed TOML — fall through with defaults
diff --git a/packages/core/src/tools/retrieve.ts b/packages/core/src/tools/retrieve.ts
index 021d1b7..80c3715 100644
--- a/packages/core/src/tools/retrieve.ts
+++ b/packages/core/src/tools/retrieve.ts
@@ -28,29 +28,33 @@ export function createRetrieveTool(callbacks: RetrieveCallbacks): ToolDefinition
 		parameters: z.object({
 			agent_id: z.string().describe("The agent_id returned by a previous summon call."),
 		}),
-		execute: async (args: Record<string, unknown>, context?: ToolExecuteContext): Promise<string> => {
+		execute: async (
+			args: Record<string, unknown>,
+			context?: ToolExecuteContext,
+		): Promise<string> => {
 			const agentId = args.agent_id as string;
 			const queueCallbacks = context?.queueCallbacks;
 
 			try {
 				let outcome: { status: "done"; result: string } | { status: "error"; error: string };
 
-			if (queueCallbacks) {
-				const childPromise = callbacks.getResult(agentId);
-				const { promise: queuePromise, cancel: cancelQueueWait } = queueCallbacks.waitForQueuedMessage();
-				const queueSignal = queuePromise.then(() => "QUEUE_INTERRUPT" as const);
+				if (queueCallbacks) {
+					const childPromise = callbacks.getResult(agentId);
+					const { promise: queuePromise, cancel: cancelQueueWait } =
+						queueCallbacks.waitForQueuedMessage();
+					const queueSignal = queuePromise.then(() => "QUEUE_INTERRUPT" as const);
 
-				const raceResult = await Promise.race([childPromise, queueSignal]);
+					const raceResult = await Promise.race([childPromise, queueSignal]);
 
-				if (raceResult === "QUEUE_INTERRUPT") {
-					const queuedMsgs = queueCallbacks.dequeueMessages();
-					const userMessages = queuedMsgs.map((m) => m.message).join("\n---\n");
-					return `The subagent (agent_id: ${agentId}) has not completed its task yet. You will need to call retrieve with this agent_id again later to get the result.\n\n[USER INTERRUPT]\nThe user has sent you message(s) while you were working. You MUST address these before continuing with your current task:\n\n${userMessages}`;
-				}
+					if (raceResult === "QUEUE_INTERRUPT") {
+						const queuedMsgs = queueCallbacks.dequeueMessages();
+						const userMessages = queuedMsgs.map((m) => m.message).join("\n---\n");
+						return `The subagent (agent_id: ${agentId}) has not completed its task yet. You will need to call retrieve with this agent_id again later to get the result.\n\n[USER INTERRUPT]\nThe user has sent you message(s) while you were working. You MUST address these before continuing with your current task:\n\n${userMessages}`;
+					}
 
-				// Child finished first — clean up the queue listener
-				cancelQueueWait();
-				outcome = raceResult;
+					// Child finished first — clean up the queue listener
+					cancelQueueWait();
+					outcome = raceResult;
 				} else {
 					outcome = await callbacks.getResult(agentId);
 				}
diff --git a/packages/core/src/tools/web-search.ts b/packages/core/src/tools/web-search.ts
index 4265aa7..7f061a5 100644
--- a/packages/core/src/tools/web-search.ts
+++ b/packages/core/src/tools/web-search.ts
@@ -70,7 +70,9 @@ export function createWebSearchTool(): ToolDefinition {
 				return `Error: Firecrawl returned HTTP ${response.status} ${response.statusText}${text ? `: ${text}` : ""}`;
 			}
 
-			let json: { data?: Array<{ title?: string; url?: string; description?: string; markdown?: string }> };
+			let json: {
+				data?: Array<{ title?: string; url?: string; description?: string; markdown?: string }>;
+			};
 			try {
 				json = await response.json();
 			} catch {
@@ -96,7 +98,7 @@ export function createWebSearchTool(): ToolDefinition {
 
 			let output = parts.join("\n\n---\n\n");
 			if (output.length > MAX_OUTPUT_CHARS) {
-				output = output.slice(0, MAX_OUTPUT_CHARS) + "\n\n[Output truncated]";
+				output = `${output.slice(0, MAX_OUTPUT_CHARS)}\n\n[Output truncated]`;
 			}
 			return output;
 		},
diff --git a/packages/core/src/tools/youtube-transcribe.ts b/packages/core/src/tools/youtube-transcribe.ts
index cfa006d..ea8ed43 100644
--- a/packages/core/src/tools/youtube-transcribe.ts
+++ b/packages/core/src/tools/youtube-transcribe.ts
@@ -41,9 +41,7 @@ function formatTime(seconds: number): string {
 
 function formatTranscript(data: TranscriptResponse): string {
 	const segments = data.segments ?? [];
-	const segmentsText = segments
-		.map((seg) => `[${formatTime(seg.start)}] ${seg.text}`)
-		.join("\n");
+	const segmentsText = segments.map((seg) => `[${formatTime(seg.start)}] ${seg.text}`).join("\n");
 
 	const output = [
 		`Video ID: ${data.video_id}`,
@@ -58,7 +56,7 @@ function formatTranscript(data: TranscriptResponse): string {
 	].join("\n");
 
 	return output.length > MAX_OUTPUT_CHARS
-		? output.slice(0, MAX_OUTPUT_CHARS) + "\n\n[Transcript truncated]"
+		? `${output.slice(0, MAX_OUTPUT_CHARS)}\n\n[Transcript truncated]`
 		: output;
 }
 
diff --git a/packages/core/src/types/index.ts b/packages/core/src/types/index.ts
index be37674..ff47f49 100644
--- a/packages/core/src/types/index.ts
+++ b/packages/core/src/types/index.ts
@@ -188,4 +188,6 @@ export interface AgentDefinition {
 	slug: string;
 	/** Default working directory for this agent (optional, absolute path) */
 	cwd?: string;
+	/** Whether this agent is a subagent (hidden from Chat Settings) */
+	is_subagent?: boolean;
 }
diff --git a/packages/core/tests/config/loader.test.ts b/packages/core/tests/config/loader.test.ts
index a572425..de025de 100644
--- a/packages/core/tests/config/loader.test.ts
+++ b/packages/core/tests/config/loader.test.ts
@@ -27,14 +27,14 @@ describe("loadConfig", () => {
 	it("parses simple string permissions", () => {
 		writeToml(`[permissions]\nread = "allow"\nedit = "deny"\n`);
 		const config = loadConfig(TMP);
-		expect(config.permissions["read"]).toBe("allow");
-		expect(config.permissions["edit"]).toBe("deny");
+		expect(config.permissions.read).toBe("allow");
+		expect(config.permissions.edit).toBe("deny");
 	});
 
 	it("parses nested pattern permissions", () => {
 		writeToml(`[permissions.bash]\n"npm test" = "allow"\n"*" = "ask"\n`);
 		const config = loadConfig(TMP);
-		const bash = config.permissions["bash"] as Record<string, string>;
+		const bash = config.permissions.bash as Record<string, string>;
 		expect(bash["npm test"]).toBe("allow");
 		expect(bash["*"]).toBe("ask");
 	});
@@ -42,27 +42,27 @@ describe("loadConfig", () => {
 	it("ignores comment lines", () => {
 		writeToml(`# this is a comment\n[permissions]\n# another comment\nread = "allow"\n`);
 		const config = loadConfig(TMP);
-		expect(config.permissions["read"]).toBe("allow");
+		expect(config.permissions.read).toBe("allow");
 	});
 
 	it("handles ~ expansion in nested keys", () => {
 		writeToml(`[permissions.read]\n"~/projects/*" = "allow"\n`);
 		const config = loadConfig(TMP);
-		const read = config.permissions["read"] as Record<string, string>;
+		const read = config.permissions.read as Record<string, string>;
 		expect(read["~/projects/*"]).toBe("allow");
 	});
 
 	it("handles $HOME expansion in nested keys", () => {
 		writeToml(`[permissions.read]\n"$HOME/docs/*" = "allow"\n`);
 		const config = loadConfig(TMP);
-		const read = config.permissions["read"] as Record<string, string>;
+		const read = config.permissions.read as Record<string, string>;
 		expect(read["$HOME/docs/*"]).toBe("allow");
 	});
 
 	it("parses quoted keys", () => {
 		writeToml(`[permissions.bash]\n"git commit *" = "allow"\n"rm *" = "deny"\n`);
 		const config = loadConfig(TMP);
-		const bash = config.permissions["bash"] as Record<string, string>;
+		const bash = config.permissions.bash as Record<string, string>;
 		expect(bash["git commit *"]).toBe("allow");
 		expect(bash["rm *"]).toBe("deny");
 	});
@@ -72,11 +72,11 @@ describe("loadConfig", () => {
 			`[permissions]\nread = "allow"\n\n[permissions.edit]\n"*" = "ask"\n"src/**" = "allow"\n\n[permissions.bash]\n"npm test" = "allow"\n"*" = "ask"\n`,
 		);
 		const config = loadConfig(TMP);
-		expect(config.permissions["read"]).toBe("allow");
-		const edit = config.permissions["edit"] as Record<string, string>;
+		expect(config.permissions.read).toBe("allow");
+		const edit = config.permissions.edit as Record<string, string>;
 		expect(edit["*"]).toBe("ask");
 		expect(edit["src/**"]).toBe("allow");
-		const bash = config.permissions["bash"] as Record<string, string>;
+		const bash = config.permissions.bash as Record<string, string>;
 		expect(bash["npm test"]).toBe("allow");
 		expect(bash["*"]).toBe("ask");
 	});
@@ -84,14 +84,14 @@ describe("loadConfig", () => {
 	it("preserves # inside quoted string keys", () => {
 		writeToml(`[permissions.bash]\n"file#1" = "allow"\n`);
 		const config = loadConfig(TMP);
-		const bash = config.permissions["bash"] as Record<string, string>;
+		const bash = config.permissions.bash as Record<string, string>;
 		expect(bash["file#1"]).toBe("allow");
 	});
 
 	it("strips inline comments on table headers", () => {
 		writeToml(`[permissions.bash] # scripts\n"*" = "allow"\n`);
 		const config = loadConfig(TMP);
-		const bash = config.permissions["bash"] as Record<string, string>;
+		const bash = config.permissions.bash as Record<string, string>;
 		expect(bash["*"]).toBe("allow");
 	});
 
@@ -100,7 +100,7 @@ describe("loadConfig", () => {
 		const pattern = `~${sep}projects${sep}*`;
 		writeToml(`[permissions.read]\n"${pattern}" = "allow"\n`);
 		const config = loadConfig(TMP);
-		const read = config.permissions["read"] as Record<string, string>;
+		const read = config.permissions.read as Record<string, string>;
 		expect(read[pattern]).toBe("allow");
 	});
 
diff --git a/packages/core/tests/llm/provider.test.ts b/packages/core/tests/llm/provider.test.ts
index 2a98556..fb5dca5 100644
--- a/packages/core/tests/llm/provider.test.ts
+++ b/packages/core/tests/llm/provider.test.ts
@@ -48,7 +48,7 @@ async function runTransform(prompt: unknown[]): Promise<unknown[]> {
 		}
 	)._middleware;
 
-	const result = await middleware[0]!.transformParams({
+	const result = await middleware[0]?.transformParams({
 		type: "stream",
 		params: { prompt },
 	});
@@ -75,7 +75,7 @@ describe("createProvider middleware", () => {
 		)._middleware;
 
 		const params = { prompt: [], temperature: 0.5 };
-		const result = (await middleware[0]!.transformParams({
+		const result = (await middleware[0]?.transformParams({
 			type: "generate",
 			params,
 		})) as Record<string, unknown>;
@@ -130,7 +130,7 @@ describe("createProvider middleware", () => {
 		// Content unchanged
 		const content = msg.content as Array<Record<string, unknown>>;
 		expect(content).toHaveLength(1);
-		expect(content[0]!.type).toBe("text");
+		expect(content[0]?.type).toBe("text");
 
 		// reasoning_content always set, even empty
 		const pm = msg.providerMetadata as Record<string, unknown>;
diff --git a/packages/frontend/electron/main.cjs b/packages/frontend/electron/main.cjs
index 2d947da..251e96c 100644
--- a/packages/frontend/electron/main.cjs
+++ b/packages/frontend/electron/main.cjs
@@ -1,33 +1,33 @@
-const { app, BrowserWindow } = require('electron');
-const path = require('path');
+const { app, BrowserWindow } = require("electron");
+const path = require("node:path");
 
 function createWindow() {
 	const win = new BrowserWindow({
 		width: 1280,
 		height: 800,
-		title: 'Dispatch',
+		title: "Dispatch",
 		webPreferences: {
 			nodeIntegration: false,
 			contextIsolation: true,
-			preload: path.join(__dirname, 'preload.cjs'),
+			preload: path.join(__dirname, "preload.cjs"),
 		},
 	});
 
-	win.loadFile(path.join(__dirname, '../dist/index.html'));
+	win.loadFile(path.join(__dirname, "../dist/index.html"));
 }
 
 app.whenReady().then(() => {
 	createWindow();
 
-	app.on('activate', () => {
+	app.on("activate", () => {
 		if (BrowserWindow.getAllWindows().length === 0) {
 			createWindow();
 		}
 	});
 });
 
-app.on('window-all-closed', () => {
-	if (process.platform !== 'darwin') {
+app.on("window-all-closed", () => {
+	if (process.platform !== "darwin") {
 		app.quit();
 	}
 });
diff --git a/packages/frontend/electron/preload.cjs b/packages/frontend/electron/preload.cjs
index c254892..14ebb26 100644
--- a/packages/frontend/electron/preload.cjs
+++ b/packages/frontend/electron/preload.cjs
@@ -1,6 +1,6 @@
-const { contextBridge } = require('electron');
+const { contextBridge } = require("electron");
 
-contextBridge.exposeInMainWorld('versions', {
+contextBridge.exposeInMainWorld("versions", {
 	electron: process.versions.electron,
 	node: process.versions.node,
 	chrome: process.versions.chrome,
diff --git a/packages/frontend/src/App.svelte b/packages/frontend/src/App.svelte
index d96cb63..a2f7327 100644
--- a/packages/frontend/src/App.svelte
+++ b/packages/frontend/src/App.svelte
@@ -186,16 +186,17 @@ onMount(() => {
 		<div class="bg-base-100 rounded-lg p-4 w-80 flex flex-col gap-3 shadow-xl">
 			<h3 class="text-sm font-semibold">Add New Key</h3>
 			<div class="flex flex-col gap-1">
-				<label class="text-xs text-base-content/60">Provider</label>
-				<select class="select select-bordered select-sm w-full" bind:value={addKeyProvider}>
+				<label class="text-xs text-base-content/60" for="add-key-provider">Provider</label>
+				<select id="add-key-provider" class="select select-bordered select-sm w-full" bind:value={addKeyProvider}>
 					<option value="anthropic">Anthropic</option>
 					<option value="opencode-go">OpenCode</option>
 					<option value="github-copilot">GitHub Copilot</option>
 				</select>
 			</div>
 			<div class="flex flex-col gap-1">
-				<label class="text-xs text-base-content/60">Key ID</label>
+				<label class="text-xs text-base-content/60" for="add-key-id">Key ID</label>
 				<input
+					id="add-key-id"
 					type="text"
 					class="input input-bordered input-sm w-full"
 					placeholder="e.g. claude-max, copilot-2"
diff --git a/packages/frontend/src/lib/components/AgentBuilder.svelte b/packages/frontend/src/lib/components/AgentBuilder.svelte
index 4a2d5d8..65fd764 100644
--- a/packages/frontend/src/lib/components/AgentBuilder.svelte
+++ b/packages/frontend/src/lib/components/AgentBuilder.svelte
@@ -24,6 +24,7 @@ const modelCache = new Map();
 		scope: string;
 		slug: string;
 		cwd?: string;
+		is_subagent?: boolean;
 	}
 
 	interface DirEntry {
@@ -65,6 +66,7 @@ const modelCache = new Map();
 	let formSkills = $state<Set<string>>(new Set());
 	let formTools = $state<Set<string>>(new Set());
 	let formModels = $state<AgentModelEntry[]>([]);
+	let formIsSubagent = $state(false);
 
 	// Model selection modal state
 	let modelModalIndex = $state<number | null>(null);
@@ -121,6 +123,7 @@ const modelCache = new Map();
 		formSkills = new Set();
 		formTools = new Set();
 		formModels = [];
+		formIsSubagent = false;
 		editing = true;
 		// Allow the effect to skip the initial population
 		setTimeout(() => { formReady = true; }, 0);
@@ -136,6 +139,7 @@ const modelCache = new Map();
 		formSkills = new Set(agent.skills);
 		formTools = new Set(agent.tools);
 		formModels = agent.models.map((m) => ({ ...m }));
+		formIsSubagent = agent.is_subagent ?? false;
 		editing = true;
 		// Allow the effect to skip the initial population
 		setTimeout(() => { formReady = true; }, 0);
@@ -260,6 +264,7 @@ const modelCache = new Map();
 			scope: formScope,
 			slug: editingSlug ?? slugify(formName.trim()),
 			...(formCwd.trim() ? { cwd: formCwd.trim() } : {}),
+			...(formIsSubagent ? { is_subagent: true } : {}),
 		};
 
 		saving = true;
@@ -317,7 +322,8 @@ const modelCache = new Map();
 	// Auto-save with debounce whenever form fields change
 	$effect(() => {
 		// Read all reactive form fields to subscribe
-		const _ = [formName, formDescription, formScope, formCwd, formSkills, formTools, formModels];
+		// noinspection: intentionally unused — reading these values subscribes the effect to them
+		void [formName, formDescription, formScope, formCwd, formSkills, formTools, formModels, formIsSubagent];
 		if (!formReady || !editing) return;
 		if (debounceTimer) clearTimeout(debounceTimer);
 		debounceTimer = setTimeout(() => {
@@ -420,6 +426,21 @@ const modelCache = new Map();
 						/>
 					</div>
 
+					<!-- Is Subagent -->
+					<div class="form-control">
+						<label class="label cursor-pointer justify-start gap-3 py-1">
+							<input
+								type="checkbox"
+								class="checkbox checkbox-sm rounded-sm"
+								bind:checked={formIsSubagent}
+							/>
+							<div>
+								<span class="label-text font-semibold">Is Subagent</span>
+								<p class="text-xs text-base-content/50">Subagents are hidden from Chat Settings and can only be used by other agents.</p>
+							</div>
+						</label>
+					</div>
+
 					<!-- Scope -->
 					<div class="form-control gap-1">
 						<label class="label py-0" for="agent-scope">
diff --git a/packages/frontend/src/lib/components/MarkdownRenderer.svelte b/packages/frontend/src/lib/components/MarkdownRenderer.svelte
index 0fbf314..de202b6 100644
--- a/packages/frontend/src/lib/components/MarkdownRenderer.svelte
+++ b/packages/frontend/src/lib/components/MarkdownRenderer.svelte
@@ -88,7 +88,7 @@ const loadCache = new Map<string, Promise<boolean>>();
 async function ensureLanguage(lang: string): Promise<boolean> {
 	const name = normalizeLang(lang);
 	if (hljs.getLanguage(name)) return true;
-	if (loadCache.has(name)) return loadCache.get(name)!;
+	if (loadCache.has(name)) return loadCache.get(name) ?? false;
 
 	const promise = (async () => {
 		try {
diff --git a/packages/frontend/src/lib/components/ModelSelector.svelte b/packages/frontend/src/lib/components/ModelSelector.svelte
index 5949e71..19ce818 100644
--- a/packages/frontend/src/lib/components/ModelSelector.svelte
+++ b/packages/frontend/src/lib/components/ModelSelector.svelte
@@ -16,6 +16,7 @@ const modelCache = new Map<string, string[]>();
 		tools: string[];
 		models: Array<{ key_id: string; model_id: string }>;
 		cwd?: string;
+		is_subagent?: boolean;
 	}
 
 	// Moves an element to document.body so modals escape the sidebar's
@@ -90,6 +91,7 @@ const modelCache = new Map<string, string[]>();
 	let modeOverride = $state<"manual" | "agent" | null>(null);
 	let mode = $derived(modeOverride ?? (activeAgentSlug ? "agent" : "manual"));
 	let agents = $state<AgentInfo[]>([]);
+	let visibleAgents = $derived(agents.filter((a) => !a.is_subagent));
 	let loadingAgents = $state(false);
 
 	$effect(() => {
@@ -206,8 +208,8 @@ const modelCache = new Map<string, string[]>();
 				modeOverride = "agent";
 				await fetchAgents();
 				// Re-apply the active agent's settings (including cwd)
-				const current = agents.find(a => a.slug === activeAgentSlug);
-				const agentToApply = current ?? agents[0] ?? null;
+				const current = visibleAgents.find(a => a.slug === activeAgentSlug);
+				const agentToApply = current ?? visibleAgents[0] ?? null;
 				if (agentToApply) {
 					onAgentChange(agentToApply);
 					// Force-update the input since the prop may not change (already set)
@@ -258,11 +260,11 @@ const modelCache = new Map<string, string[]>();
 				<span class="loading loading-spinner loading-xs"></span>
 				Loading agents...
 			</div>
-		{:else if agents.length === 0}
+		{:else if visibleAgents.length === 0}
 			<p class="text-base-content/50 text-sm py-2">No agents configured.</p>
 		{:else}
 			<div class="flex flex-col gap-1.5">
-				{#each agents as agent (agent.slug + ":" + agent.scope)}
+				{#each visibleAgents as agent (agent.slug + ":" + agent.scope)}
 					<button
 						class="w-full text-left rounded-lg px-3 py-2 transition-colors {activeAgentSlug === agent.slug ? 'bg-primary text-primary-content' : 'bg-base-300 hover:bg-base-200'}"
 						onclick={() => {
diff --git a/packages/frontend/src/lib/components/ModelStatus.svelte b/packages/frontend/src/lib/components/ModelStatus.svelte
index d6ff0f5..57c5efd 100644
--- a/packages/frontend/src/lib/components/ModelStatus.svelte
+++ b/packages/frontend/src/lib/components/ModelStatus.svelte
@@ -48,8 +48,6 @@ let keyModalError = $state<string | null>(null);
 let keyModalSaving = $state(false);
 let removingKey = $state<string | null>(null);
 
-
-
 async function loadCredentialStatus(): Promise<void> {
 	try {
 		const res = await fetch(`${apiBase}/models/credentials-status`);
@@ -173,7 +171,7 @@ function timeAgo(ts: number | null): string {
 
 function truncate(str: string | null, max: number): string {
 	if (!str) return "";
-	return str.length > max ? str.slice(0, max) + "..." : str;
+	return str.length > max ? `${str.slice(0, max)}...` : str;
 }
 </script>
 
diff --git a/packages/frontend/src/lib/components/SettingsPanel.svelte b/packages/frontend/src/lib/components/SettingsPanel.svelte
index c19fe45..eadfef8 100644
--- a/packages/frontend/src/lib/components/SettingsPanel.svelte
+++ b/packages/frontend/src/lib/components/SettingsPanel.svelte
@@ -25,14 +25,18 @@ function saveBackendUrl(): void {
 	config.setApiBase(trimmed);
 	backendUrl = trimmed;
 	backendUrlSaved = true;
-	setTimeout(() => { backendUrlSaved = false; }, 2000);
+	setTimeout(() => {
+		backendUrlSaved = false;
+	}, 2000);
 }
 
 function resetBackendUrl(): void {
 	config.setApiBase(config.defaultApiBase);
 	backendUrl = config.defaultApiBase;
 	backendUrlSaved = true;
-	setTimeout(() => { backendUrlSaved = false; }, 2000);
+	setTimeout(() => {
+		backendUrlSaved = false;
+	}, 2000);
 }
 
 async function loadSettings(): Promise<void> {
diff --git a/packages/frontend/src/lib/components/SidebarPanel.svelte b/packages/frontend/src/lib/components/SidebarPanel.svelte
index e89e351..371561a 100644
--- a/packages/frontend/src/lib/components/SidebarPanel.svelte
+++ b/packages/frontend/src/lib/components/SidebarPanel.svelte
@@ -10,6 +10,15 @@ import SkillsBrowser from "./SkillsBrowser.svelte";
 import TaskListPanel from "./TaskListPanel.svelte";
 import ToolPermissions from "./ToolPermissions.svelte";
 
+interface AgentInfo {
+	slug: string;
+	scope: string;
+	skills: string[];
+	tools: string[];
+	models: Array<{ key_id: string; model_id: string }>;
+	cwd?: string;
+}
+
 const {
 	keys = [],
 	tasks = [],
@@ -23,7 +32,7 @@ const {
 	onKeyChange,
 	onModelChange,
 	onReasoningChange,
-	onAgentChange = (_agent: any) => {},
+	onAgentChange = (_agent: AgentInfo | null) => {},
 	onWorkingDirectoryChange = (_dir: string | null) => {},
 	onAddKey = () => {},
 }: {
@@ -39,7 +48,7 @@ const {
 	onKeyChange: (keyId: string) => void;
 	onModelChange: (keyId: string, modelId: string) => void;
 	onReasoningChange: (effort: string) => void;
-	onAgentChange?: (agent: any) => void;
+	onAgentChange?: (agent: AgentInfo | null) => void;
 	onWorkingDirectoryChange?: (dir: string | null) => void;
 	onAddKey?: () => void;
 } = $props();
@@ -72,7 +81,7 @@ function addPanel() {
 function panelClass(selected: string): string {
 	const base = "bg-base-200 rounded-lg p-3 flex flex-col min-h-0";
 	const fill = selected === "Key Usage" || selected === "Claude Reset" || selected === "Tasks";
-	return fill ? base + " flex-1" : base;
+	return fill ? `${base} flex-1` : base;
 }
 
 function contentClass(selected: string): string {
diff --git a/packages/frontend/src/lib/components/SkillsBrowser.svelte b/packages/frontend/src/lib/components/SkillsBrowser.svelte
index add43e4..e697732 100644
--- a/packages/frontend/src/lib/components/SkillsBrowser.svelte
+++ b/packages/frontend/src/lib/components/SkillsBrowser.svelte
@@ -77,7 +77,7 @@ function dirKey(group: DirGroup): string {
 function isChecked(skill: Skill): boolean {
 	const key = skillKey(skill);
 	if (externalMode) {
-		return checkedSkills!.has(key);
+		return checkedSkills?.has(key) ?? false;
 	}
 	return appSettings.skillChecks[key] === true;
 }
@@ -90,7 +90,7 @@ function isInjected(skill: Skill): boolean {
 function toggleCheck(skill: Skill): void {
 	const key = skillKey(skill);
 	if (externalMode) {
-		onSkillToggle!(key, !checkedSkills!.has(key));
+		onSkillToggle?.(key, !checkedSkills?.has(key));
 		return;
 	}
 	appSettings.skillChecks = { ...appSettings.skillChecks, [key]: !isChecked(skill) };
@@ -156,7 +156,7 @@ $effect(() => {
 
 const checkedCount = $derived(
 	externalMode
-		? checkedSkills!.size
+		? (checkedSkills?.size ?? 0)
 		: Object.values(appSettings.skillChecks).filter((v) => v).length,
 );
 
diff --git a/packages/frontend/src/lib/components/ToolPermissions.svelte b/packages/frontend/src/lib/components/ToolPermissions.svelte
index 6533c7b..7fdaad3 100644
--- a/packages/frontend/src/lib/components/ToolPermissions.svelte
+++ b/packages/frontend/src/lib/components/ToolPermissions.svelte
@@ -22,6 +22,16 @@ const toolPermissions: ToolPermission[] = [
 		label: "Summon agents",
 		description: "Allow the AI to spawn child agents to work on tasks",
 	},
+	{
+		id: "web_search",
+		label: "Web search",
+		description: "Allow the AI to search the web via Firecrawl",
+	},
+	{
+		id: "youtube_transcribe",
+		label: "YouTube transcripts",
+		description: "Allow the AI to fetch YouTube video transcripts",
+	},
 ];
 
 const {
@@ -42,7 +52,7 @@ const {
 const externalMode = $derived(checkedTools !== null && onToolToggle !== null);
 
 function isChecked(id: string): boolean {
-	if (externalMode) return checkedTools!.has(id);
+	if (externalMode) return checkedTools?.has(id) ?? false;
 	return appSettings.toolPerms[id] === true;
 }
 
@@ -67,7 +77,7 @@ async function loadPermissions(): Promise<void> {
 
 function togglePermission(id: string): void {
 	if (externalMode) {
-		onToolToggle!(id, !checkedTools!.has(id));
+		onToolToggle?.(id, !checkedTools?.has(id));
 		return;
 	}
 	appSettings.toolPerms = { ...appSettings.toolPerms, [id]: !appSettings.toolPerms[id] };
diff --git a/packages/frontend/src/lib/settings.svelte.ts b/packages/frontend/src/lib/settings.svelte.ts
index 1352a0c..2828e7c 100644
--- a/packages/frontend/src/lib/settings.svelte.ts
+++ b/packages/frontend/src/lib/settings.svelte.ts
@@ -9,6 +9,8 @@ let toolPerms = $state<Record<string, boolean>>({
 	bash: false,
 	summon: false,
 	external_directory: false,
+	web_search: false,
+	youtube_transcribe: false,
 });
 let savedToolPerms = $state<Record<string, boolean>>({
 	read: true,
@@ -16,6 +18,8 @@ let savedToolPerms = $state<Record<string, boolean>>({
 	bash: false,
 	summon: false,
 	external_directory: false,
+	web_search: false,
+	youtube_transcribe: false,
 });
 let skillChecks = $state<Record<string, boolean>>({});
 
diff --git a/packages/frontend/src/lib/tabs.svelte.ts b/packages/frontend/src/lib/tabs.svelte.ts
index d186ccb..7f4d768 100644
--- a/packages/frontend/src/lib/tabs.svelte.ts
+++ b/packages/frontend/src/lib/tabs.svelte.ts
@@ -465,24 +465,24 @@ function createTabStore() {
 				};
 				// Only add if we don't already have this tab
 				if (!getTabById(newTabEvent.id)) {
-				const tab: Tab = {
-					id: newTabEvent.id,
-					title: newTabEvent.title,
-					messages: [],
-					agentStatus: "running",
-					keyId: newTabEvent.keyId ?? null,
-					modelId: newTabEvent.modelId ?? null,
-					reasoningEffort: "max",
-					currentAssistantId: null,
-					tasks: [],
-					injectedSkills: [],
-					parentTabId: newTabEvent.parentTabId ?? null,
-					persistent: newTabEvent.parentTabId == null,
-					agentSlug: null,
-					agentScope: null,
-					workingDirectory: null,
-					queuedMessages: [],
-				};
+					const tab: Tab = {
+						id: newTabEvent.id,
+						title: newTabEvent.title,
+						messages: [],
+						agentStatus: "running",
+						keyId: newTabEvent.keyId ?? null,
+						modelId: newTabEvent.modelId ?? null,
+						reasoningEffort: "max",
+						currentAssistantId: null,
+						tasks: [],
+						injectedSkills: [],
+						parentTabId: newTabEvent.parentTabId ?? null,
+						persistent: newTabEvent.parentTabId == null,
+						agentSlug: null,
+						agentScope: null,
+						workingDirectory: null,
+						queuedMessages: [],
+					};
 					tabs = [...tabs, tab];
 				}
 				break;
@@ -506,8 +506,7 @@ function createTabStore() {
 					// Also add as a user chat message if not already present
 					const tabAfterQm = getTabById(tabId);
 					const existingMsg = tabAfterQm?.messages.find(
-						(m) =>
-							m.id === `queued-${mqEvent.messageId}` || m.id === mqEvent.messageId,
+						(m) => m.id === `queued-${mqEvent.messageId}` || m.id === mqEvent.messageId,
 					);
 					if (!existingMsg) {
 						const userMsg: ChatMessage = {
@@ -557,15 +556,13 @@ function createTabStore() {
 
 					// Mark the current assistant message as done streaming
 					const result = rest.map((m) =>
-						m.id === currentAssistantId
-							? { ...m, isStreaming: false }
-							: m,
+						m.id === currentAssistantId ? { ...m, isStreaming: false } : m,
 					);
 
 					// Insert consumed messages right after the current assistant message
 					let insertIdx = result.length;
 					for (let i = result.length - 1; i >= 0; i--) {
-						if (result[i].id === currentAssistantId) {
+						if (result[i]?.id === currentAssistantId) {
 							insertIdx = i + 1;
 							break;
 						}
@@ -633,7 +630,9 @@ function createTabStore() {
 				}>;
 			};
 			const agents = data.agents ?? [];
-			const defaultAgent = agents.find((a: { slug: string; scope: string }) => a.slug === "default" && a.scope === "global");
+			const defaultAgent = agents.find(
+				(a: { slug: string; scope: string }) => a.slug === "default" && a.scope === "global",
+			);
 			if (!defaultAgent) return;
 
 			const tab = getTabById(tabId);
@@ -747,10 +746,13 @@ function createTabStore() {
 			queueId = generateId();
 			userMsg.id = `queued-${queueId}`;
 			// Pre-populate queuedMessages so WS event finds it immediately
-			tab.queuedMessages = [...tab.queuedMessages, { id: queueId, message: text, timestamp: Date.now() }];
+			tab.queuedMessages = [
+				...tab.queuedMessages,
+				{ id: queueId, message: text, timestamp: Date.now() },
+			];
 		}
 
-		updateTab(tab.id, { messages: [...tab.messages, userMsg] });		// Generate title from first user message
+		updateTab(tab.id, { messages: [...tab.messages, userMsg] }); // Generate title from first user message
 		if (tab.messages.length === 0 || (tab.messages.length === 1 && tab.title === "New Tab")) {
 			const titleText = text.length > 50 ? `${text.slice(0, 47)}...` : text;
 			updateTab(tab.id, { title: titleText });
@@ -818,9 +820,7 @@ function createTabStore() {
 						});
 					}
 					updateMessages(tab.id, (msgs) =>
-						msgs.map((m) =>
-							m.id === `queued-${queueId}` ? { ...m, id: generateId() } : m,
-						),
+						msgs.map((m) => (m.id === `queued-${queueId}` ? { ...m, id: generateId() } : m)),
 					);
 				}
 				const errMsg: ChatMessage = {
@@ -858,9 +858,7 @@ function createTabStore() {
 						}
 						// Restore the message to a normal (non-queued) ID
 						updateMessages(tab.id, (msgs) =>
-							msgs.map((m) =>
-								m.id === `queued-${queueId}` ? { ...m, id: generateId() } : m,
-							),
+							msgs.map((m) => (m.id === `queued-${queueId}` ? { ...m, id: generateId() } : m)),
 						);
 					}
 				}
@@ -875,9 +873,7 @@ function createTabStore() {
 					});
 				}
 				updateMessages(tab.id, (msgs) =>
-					msgs.map((m) =>
-						m.id === `queued-${queueId}` ? { ...m, id: generateId() } : m,
-					),
+					msgs.map((m) => (m.id === `queued-${queueId}` ? { ...m, id: generateId() } : m)),
 				);
 			}
 			const errMsg: ChatMessage = {
diff --git a/packages/frontend/vite.config.ts b/packages/frontend/vite.config.ts
index 1b9921b..ee55efa 100644
--- a/packages/frontend/vite.config.ts
+++ b/packages/frontend/vite.config.ts
@@ -3,7 +3,7 @@ import tailwindcss from "@tailwindcss/vite";
 import { defineConfig } from "vite";
 
 export default defineConfig({
-	base: './',
+	base: "./",
 	plugins: [tailwindcss(), svelte()],
 	server: {
 		port: 5173,