feat(router): add aiChat tRPC sub-router

CRUD for chat sessions and messages, used by both home and contextual
channels. No UI consumer yet — added ahead of refactor.

src/main/router/ai-chat.ts

@@ -0,0 +1,105 @@
+// adiuvAI/src/main/router/ai-chat.ts
+import { initTRPC } from '@trpc/server';
+import { z } from 'zod';
+import { eq, desc, asc } from 'drizzle-orm';
+import { getDb } from '../db';
+import { aiChatSessions, aiChatMessages } from '../db/schema';
+import type { TRPCContext } from '../ipc';
+
+const t = initTRPC.context<TRPCContext>().create();
+const router = t.router;
+const publicProcedure = t.procedure;
+
+const ChannelSchema = z.enum(['home', 'contextual']);
+const RoleSchema = z.enum(['user', 'assistant', 'system']);
+
+export const aiChatRouter = router({
+  listSessions: publicProcedure
+    .input(z.object({ channel: ChannelSchema }))
+    .query(({ input }) => {
+      return getDb()
+        .select()
+        .from(aiChatSessions)
+        .where(eq(aiChatSessions.channel, input.channel))
+        .orderBy(desc(aiChatSessions.updatedAt))
+        .all();
+    }),
+
+  getSession: publicProcedure
+    .input(z.object({ id: z.string() }))
+    .query(({ input }) => {
+      const db = getDb();
+      const session = db
+        .select()
+        .from(aiChatSessions)
+        .where(eq(aiChatSessions.id, input.id))
+        .get();
+      if (!session) return null;
+      const messages = db
+        .select()
+        .from(aiChatMessages)
+        .where(eq(aiChatMessages.sessionId, input.id))
+        .orderBy(asc(aiChatMessages.createdAt))
+        .all();
+      return { session, messages };
+    }),
+
+  createSession: publicProcedure
+    .input(z.object({
+      channel: ChannelSchema,
+      initialScope: z.string().optional(),
+    }))
+    .mutation(({ input }) => {
+      const db = getDb();
+      const id = crypto.randomUUID();
+      const now = Date.now();
+      db.insert(aiChatSessions).values({
+        id,
+        channel: input.channel,
+        title: null,
+        createdAt: now,
+        updatedAt: now,
+        lastScope: input.initialScope ?? null,
+      }).run();
+      return { id };
+    }),
+
+  appendMessage: publicProcedure
+    .input(z.object({
+      sessionId: z.string(),
+      role: RoleSchema,
+      content: z.string(),
+      toolCalls: z.string().optional(),
+      toolResults: z.string().optional(),
+      scope: z.string().optional(),
+    }))
+    .mutation(({ input }) => {
+      const db = getDb();
+      const id = crypto.randomUUID();
+      const now = Date.now();
+      db.insert(aiChatMessages).values({
+        id,
+        sessionId: input.sessionId,
+        role: input.role,
+        content: input.content,
+        toolCalls: input.toolCalls ?? null,
+        toolResults: input.toolResults ?? null,
+        scope: input.scope ?? null,
+        createdAt: now,
+      }).run();
+      db.update(aiChatSessions)
+        .set({ updatedAt: now, lastScope: input.scope ?? null })
+        .where(eq(aiChatSessions.id, input.sessionId))
+        .run();
+      return { id };
+    }),
+
+  deleteSession: publicProcedure
+    .input(z.object({ id: z.string() }))
+    .mutation(({ input }) => {
+      const db = getDb();
+      db.delete(aiChatMessages).where(eq(aiChatMessages.sessionId, input.id)).run();
+      db.delete(aiChatSessions).where(eq(aiChatSessions.id, input.id)).run();
+      return { ok: true };
+    }),
+});

src/main/router/index.ts

@@ -18,6 +18,7 @@ import { getAuthManager, AuthError } from '../auth/auth-manager';
 import { detectFormatPrefs, detectLanguage } from '../auth/locale-defaults';
 import type { TRPCContext } from '../ipc';
 import { projectFoldersRouter } from './projectFolders';
+import { aiChatRouter } from './ai-chat';
 
 const t = initTRPC.context<TRPCContext>().create();
 
@@ -1856,6 +1857,7 @@ export const appRouter = router({
   agent: agentRouter,
   memory: memoryRouter,
   projectFolders: projectFoldersRouter,
+  aiChat: aiChatRouter,
 });
 
 export type AppRouter = typeof appRouter;