feat: add MCP server with streamable HTTP transport at /mcp

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/server/index.ts

@@ -1,6 +1,7 @@
 import { Hono } from "hono";
 import { serveStatic } from "hono/bun";
 import { seedDefaults } from "../db/seed.ts";
+import { mcpRoutes } from "./mcp/index.ts";
 import { requireAuth } from "./middleware/auth.ts";
 import { authRoutes } from "./routes/auth.ts";
 import { categoryRoutes } from "./routes/categories.ts";
@@ -41,6 +42,11 @@ app.route("/api/settings", settingsRoutes);
 app.route("/api/threads", threadRoutes);
 app.route("/api/setups", setupRoutes);
 
+// MCP server (conditionally mounted)
+if (process.env.GEARBOX_MCP !== "false") {
+	app.route("/mcp", mcpRoutes);
+}
+
 // Serve uploaded images
 app.use("/uploads/*", serveStatic({ root: "./" }));