feat: tab system with per-tab agents, DB persistence, and DaisyUI tabs-lift UI

- Add tabs, messages, and settings tables to SQLite database
- Backend: refactor AgentManager to manage per-tab Agent instances via Map<tabId, TabAgent>
- Backend: WebSocket events tagged with tabId for multiplexing
- Backend: tab CRUD routes (create, list, update, archive, messages)
- Backend: persist user and assistant messages to DB during chat
- Frontend: new tabStore replaces single chatStore with multi-tab reactive state
- Frontend: TabBar component using DaisyUI tabs-lift style with status dots
- Frontend: Settings sidebar panel for title generation model selection
- Frontend: wire ChatPanel, ChatInput, Header to use tabStore
- Fix HMR listener accumulation via wsClient.clearCallbacks()
- Delete old single-chat chatStore (chat.svelte.ts)

1 files changed, 81 insertions, 0 deletions

diff --git a/packages/api/src/routes/tabs.ts b/packages/api/src/routes/tabs.ts
new file mode 100644
index 0000000..7fe05d9
--- /dev/null
+++ b/packages/api/src/routes/tabs.ts
@@ -0,0 +1,81 @@
+import { Hono } from "hono";
+import {
+	createTab,
+	getTab,
+	listOpenTabs,
+	updateTabTitle,
+	updateTabModel,
+	updateTabStatus,
+	archiveTab,
+	getMessagesForTab,
+	getSetting,
+	setSetting,
+} from "@dispatch/core";
+
+export const tabsRoutes = new Hono();
+
+let getAgentManager: () => { stopTab(id: string): void; deleteTab(id: string): void } | null = () => null;
+
+export function setTabsAgentManager(getter: () => { stopTab(id: string): void; deleteTab(id: string): void } | null): void {
+	getAgentManager = getter;
+}
+
+tabsRoutes.get("/", (c) => {
+	const tabs = listOpenTabs();
+	return c.json({ tabs });
+});
+
+tabsRoutes.post("/", async (c) => {
+	const body = await c.req.json<{ id?: string; title?: string }>();
+	const id = body.id ?? crypto.randomUUID();
+	const title = body.title ?? "New Tab";
+	const tab = createTab(id, title);
+	return c.json(tab);
+});
+
+// Settings routes (must be before /:id to avoid conflict)
+tabsRoutes.get("/settings/title-model", (c) => {
+	const keyId = getSetting("title_model_key_id");
+	const modelId = getSetting("title_model_id");
+	return c.json({ keyId, modelId });
+});
+
+tabsRoutes.put("/settings/title-model", async (c) => {
+	const body = await c.req.json<{ keyId?: string; modelId?: string }>();
+	if (body.keyId) setSetting("title_model_key_id", body.keyId);
+	if (body.modelId) setSetting("title_model_id", body.modelId);
+	return c.json({ success: true });
+});
+
+tabsRoutes.get("/:id", (c) => {
+	const id = c.req.param("id");
+	const tab = getTab(id);
+	if (!tab) return c.json({ error: "tab not found" }, 404);
+	return c.json(tab);
+});
+
+tabsRoutes.get("/:id/messages", (c) => {
+	const id = c.req.param("id");
+	const messages = getMessagesForTab(id);
+	return c.json({ messages });
+});
+
+tabsRoutes.patch("/:id", async (c) => {
+	const id = c.req.param("id");
+	const body = await c.req.json<{ title?: string; keyId?: string; modelId?: string; status?: string }>();
+	if (body.title !== undefined) updateTabTitle(id, body.title);
+	if (body.keyId !== undefined || body.modelId !== undefined) {
+		updateTabModel(id, body.keyId ?? null, body.modelId ?? null);
+	}
+	if (body.status !== undefined) updateTabStatus(id, body.status);
+	const tab = getTab(id);
+	return c.json(tab);
+});
+
+tabsRoutes.delete("/:id", (c) => {
+	const id = c.req.param("id");
+	const mgr = getAgentManager();
+	if (mgr) mgr.deleteTab(id);
+	archiveTab(id);
+	return c.json({ success: true });
+});