refactor(transport-http,host-bin): transport-http owns its Bun.serve (fix log scope)

Make transport-http a full-fidelity extension that runs its own Bun.serve
inside activate(host) — symmetric with transport-ws. The Hono app is now built
with the extension-scoped host, so all HTTP edge logs are correctly attributed
extensionId=transport-http instead of the host-bin __host__ scope (verified
live in the journal).

- transport-http: createTransportHttpExtension() factory; activate builds the
  app + Bun.serve, reads host.config httpPort (?? 24203); deactivate stops it.
- host-bin: drops the HTTP Bun.serve + createServer call; config.ts maps
  BACKEND_PORT/PORT -> httpPort. host-bin now serves no transport (both
  transports self-serve); boot log -> 'Dispatch booted'.
- +5 bun lifecycle tests wired into test:bun.

No contract change (composition wiring). Verified live: HTTP serves on :24203;
journal edge logs now scoped transport-http. typecheck clean, 498 vitest + 89
bun, biome clean.

5 files changed, 265 insertions, 26 deletions

diff --git a/packages/host-bin/src/config.ts b/packages/host-bin/src/config.ts
index cbf7bce..cf6b0ce 100644
--- a/packages/host-bin/src/config.ts
+++ b/packages/host-bin/src/config.ts
@@ -20,6 +20,14 @@ export function envToConfigMap(
 		map["provider.openai-compat.model"] = model;
 	}
 
+	const httpPort = env.BACKEND_PORT ?? env.PORT;
+	if (httpPort !== undefined) {
+		const n = Number(httpPort);
+		if (Number.isFinite(n) && n > 0) {
+			map.httpPort = n;
+		}
+	}
+
 	return map;
 }
 
diff --git a/packages/host-bin/src/main.ts b/packages/host-bin/src/main.ts
index 68cbbdd..b18f105 100644
--- a/packages/host-bin/src/main.ts
+++ b/packages/host-bin/src/main.ts
@@ -24,7 +24,7 @@ import { createSqliteStorage, extension as storageSqliteExt } from "@dispatch/st
 import { createLoadedExtensionsExtension } from "@dispatch/surface-loaded-extensions";
 import { createSurfaceRegistryExtension } from "@dispatch/surface-registry";
 import { extension as toolReadFileExt } from "@dispatch/tool-read-file";
-import { createServer, extension as transportHttpExt } from "@dispatch/transport-http";
+import { createTransportHttpExtension } from "@dispatch/transport-http";
 import { createTransportWsExtension } from "@dispatch/transport-ws";
 import type { ChildHandle } from "./collector-supervisor.js";
 import { createCollectorSupervisor } from "./collector-supervisor.js";
@@ -63,7 +63,7 @@ const CORE_EXTENSIONS: readonly Extension[] = [
 		credentials: [{ name: "opencode", providerId: "openai-compat" }],
 	}),
 	sessionOrchestratorExt,
-	transportHttpExt,
+	createTransportHttpExtension(),
 	// Surface extensions — dependency order: surface-registry first, then consumers.
 	createSurfaceRegistryExtension(),
 	createTransportWsExtension(),
@@ -125,13 +125,6 @@ async function boot(): Promise<void> {
 		}
 	}
 
-	const hostAPI = host.getHostAPI();
-	const app = createServer(hostAPI);
-
-	// Port precedence: BACKEND_PORT (the rewrite's assigned port) → PORT → default.
-	const port = Number(process.env.BACKEND_PORT) || Number(process.env.PORT) || 24203;
-	const server = Bun.serve({ fetch: app.fetch, port });
-
 	const shutdown = async () => {
 		logger.info("Shutting down — draining collector");
 		await supervisor.stop();
@@ -140,8 +133,8 @@ async function boot(): Promise<void> {
 	process.on("SIGINT", shutdown);
 	process.on("SIGTERM", shutdown);
 
-	logger.info(`Dispatch listening on http://localhost:${server.port}`);
-	console.info(`Dispatch listening on http://localhost:${server.port}`);
+	logger.info("Dispatch booted");
+	console.info("Dispatch booted");
 }
 
 boot().catch((err) => {
diff --git a/packages/transport-http/src/extension.ts b/packages/transport-http/src/extension.ts
index dda722e..adbf87f 100644
--- a/packages/transport-http/src/extension.ts
+++ b/packages/transport-http/src/extension.ts
@@ -1,5 +1,4 @@
 import type { Extension, HostAPI, Manifest } from "@dispatch/kernel";
-import type { Hono } from "hono";
 import { createApp } from "./app.js";
 import {
 	conversationStoreHandle,
@@ -19,18 +18,44 @@ export const manifest: Manifest = {
 	activation: "eager",
 };
 
-export interface CreateServerOptions {
-	readonly port?: number;
-}
+export function createTransportHttpExtension(): Extension & {
+	readonly _testServer: ReturnType<typeof Bun.serve> | undefined;
+} {
+	let server: ReturnType<typeof Bun.serve> | undefined;
 
-export function createServer(host: HostAPI, _opts?: CreateServerOptions): Hono {
-	const conversationStore = host.getService(conversationStoreHandle);
-	const orchestrator = host.getService(sessionOrchestratorHandle);
-	const credentialStore = host.getService(credentialStoreHandle);
-	return createApp({ conversationStore, orchestrator, credentialStore, logger: host.logger });
-}
+	return {
+		get _testServer() {
+			return server;
+		},
+		manifest,
+		async activate(host: HostAPI) {
+			const conversationStore = host.getService(conversationStoreHandle);
+			const orchestrator = host.getService(sessionOrchestratorHandle);
+			const credentialStore = host.getService(credentialStoreHandle);
+			const logger = host.logger;
 
-export const extension: Extension = {
-	manifest,
-	activate: (_host: HostAPI) => {},
-};
+			const app = createApp({
+				conversationStore,
+				orchestrator,
+				credentialStore,
+				logger,
+			});
+
+			const port = host.config.get<number>("httpPort") ?? 24203;
+
+			server = Bun.serve({
+				port,
+				fetch: app.fetch,
+			});
+
+			logger.info("transport-http: listening", { port });
+		},
+
+		deactivate() {
+			if (server) {
+				server.stop();
+				server = undefined;
+			}
+		},
+	};
+}
diff --git a/packages/transport-http/src/index.ts b/packages/transport-http/src/index.ts
index d92319c..171cf6a 100644
--- a/packages/transport-http/src/index.ts
+++ b/packages/transport-http/src/index.ts
@@ -1,6 +1,6 @@
 export type { CreateServerOptions } from "./app.js";
 export { createApp } from "./app.js";
-export { createServer, extension, manifest } from "./extension.js";
+export { createTransportHttpExtension, manifest } from "./extension.js";
 export type { ChatCommand, ParseError, ParseResult, SinceSeqResult } from "./logic.js";
 export {
 	isParseError,
diff --git a/packages/transport-http/src/server.bun.test.ts b/packages/transport-http/src/server.bun.test.ts
new file mode 100644
index 0000000..e824d18
--- /dev/null
+++ b/packages/transport-http/src/server.bun.test.ts
@@ -0,0 +1,213 @@
+import { afterEach, describe, expect, test } from "bun:test";
+import type { ConfigAccess, HostAPI, Logger } from "@dispatch/kernel";
+import { createApp } from "./app.js";
+import { createTransportHttpExtension } from "./index.js";
+import type { ConversationStore, CredentialStore, SessionOrchestrator } from "./seam.js";
+
+function fakeLogger(): Logger {
+	return {
+		debug() {},
+		info() {},
+		warn() {},
+		error() {},
+		child() {
+			return fakeLogger();
+		},
+		span() {
+			return {
+				id: "fake-span",
+				log: fakeLogger(),
+				setAttributes() {},
+				addLink() {},
+				child() {
+					return this;
+				},
+				end() {},
+			};
+		},
+	};
+}
+
+function fakeConversationStore(): ConversationStore {
+	return {
+		async append() {},
+		async load() {
+			return [];
+		},
+		async loadSince() {
+			return [];
+		},
+	};
+}
+
+function fakeOrchestrator(): SessionOrchestrator {
+	return {
+		async handleMessage() {},
+	};
+}
+
+function fakeCredentialStore(): CredentialStore {
+	return {
+		resolve() {
+			return undefined;
+		},
+		async listCatalog() {
+			return [];
+		},
+	};
+}
+
+function fakeConfig(overrides: Record<string, unknown> = {}): ConfigAccess {
+	return {
+		get<T>(key: string): T | undefined {
+			return overrides[key] as T | undefined;
+		},
+		getAll() {
+			return overrides;
+		},
+	};
+}
+
+const SERVICES = new Map<string, unknown>([
+	["conversation-store/store", fakeConversationStore()],
+	["session-orchestrator/orchestrator", fakeOrchestrator()],
+	["credential-store/registry", fakeCredentialStore()],
+]);
+
+function createFakeHostAPI(configOverrides: Record<string, unknown> = {}): HostAPI {
+	return {
+		defineTool() {},
+		defineProvider() {},
+		defineAuth() {},
+		on() {
+			return () => {};
+		},
+		addFilter() {
+			return () => {};
+		},
+		provideService() {},
+		getService(handle) {
+			return SERVICES.get(handle.id) as never;
+		},
+		storage() {
+			return {
+				get: async () => null,
+				set: async () => {},
+				delete: async () => {},
+				has: async () => false,
+				keys: async () => [],
+			};
+		},
+		config: fakeConfig(configOverrides),
+		secrets: { get: async () => null, set: async () => {}, delete: async () => {} },
+		permissions: { check: async () => ({ allowed: true }) },
+		events: { emit() {} },
+		logger: fakeLogger(),
+		getProviders() {
+			return new Map();
+		},
+		getTools() {
+			return new Map();
+		},
+		getAuthProviders() {
+			return new Map();
+		},
+		getAuthProvider() {
+			return undefined;
+		},
+		getExtensions() {
+			return [];
+		},
+		scheduler: { register() {} },
+	};
+}
+
+// ── Server helper (mirrors extension.ts logic for direct testing) ────────
+
+function startServer(port = 0) {
+	const app = createApp({
+		conversationStore: fakeConversationStore(),
+		orchestrator: fakeOrchestrator(),
+		credentialStore: fakeCredentialStore(),
+	});
+	return Bun.serve({ port, fetch: app.fetch });
+}
+
+// ── Tests ────────────────────────────────────────────────────────────────
+
+describe("serves HTTP on the configured port", () => {
+	let server: ReturnType<typeof Bun.serve>;
+	let port: number;
+
+	afterEach(() => {
+		server.stop();
+	});
+
+	test("GET /health returns 200", async () => {
+		server = startServer();
+		port = server.port as number;
+
+		const res = await fetch(`http://localhost:${port}/health`);
+		expect(res.status).toBe(200);
+		const body = (await res.json()) as { ok: boolean };
+		expect(body.ok).toBe(true);
+	});
+
+	test("POST /chat returns NDJSON", async () => {
+		server = startServer();
+		port = server.port as number;
+
+		const res = await fetch(`http://localhost:${port}/chat`, {
+			method: "POST",
+			headers: { "Content-Type": "application/json" },
+			body: JSON.stringify({ message: "hi", conversationId: "conv1" }),
+		});
+		expect(res.status).toBe(200);
+		expect(res.headers.get("Content-Type")).toBe("application/x-ndjson");
+	});
+
+	test("GET /models returns 200", async () => {
+		server = startServer();
+		port = server.port as number;
+
+		const res = await fetch(`http://localhost:${port}/models`);
+		expect(res.status).toBe(200);
+		const body = (await res.json()) as { models: readonly string[] };
+		expect(body.models).toEqual([]);
+	});
+
+	test("GET /conversations/:id returns 200", async () => {
+		server = startServer();
+		port = server.port as number;
+
+		const res = await fetch(`http://localhost:${port}/conversations/conv1`);
+		expect(res.status).toBe(200);
+		const body = (await res.json()) as { chunks: readonly unknown[]; latestSeq: number };
+		expect(body.chunks).toEqual([]);
+		expect(body.latestSeq).toBe(0);
+	});
+});
+
+describe("extension lifecycle", () => {
+	test("activate starts server on config port and deactivate stops it", async () => {
+		const ext = createTransportHttpExtension();
+		const host = createFakeHostAPI({ httpPort: 0 });
+		await ext.activate(host);
+		const server = ext._testServer;
+		expect(server).toBeDefined();
+		const port = server?.port as number;
+		expect(port).toBeGreaterThan(0);
+
+		const res = await fetch(`http://localhost:${port}/health`);
+		expect(res.status).toBe(200);
+
+		ext.deactivate?.();
+
+		try {
+			await fetch(`http://localhost:${port}/health`);
+			expect(true).toBe(false);
+		} catch {
+			// expected — server stopped
+		}
+	});
+});