Add minimal stock listing app: actions, Postgres schema, stocks page, Claude Agent SDK harness

- Add stocks table (server/db) with list/get/add/update/delete actions, scoped
  per user, backing both the chat agent and the /stocks UI via
  useActionQuery/useActionMutation
- Add mobile-first /stocks page (shadcn table/cards, watchlist, search) and
  wire it into the sidebar, navigation state, and view-screen context
- Install the platform's Claude Agent SDK harness (server/plugins,
  server/routes/api/claude-agent) so the app agent runs on the platform's own
  Claude subscription instead of the Builder.io gateway; fix the vendored
  turn.post.ts route to resolve the session and wrap it in
  runWithRequestContext, since custom /api/ routes aren't auto-wrapped in
  request context the way /_agent-native/actions/* are
- Add shadcn table/badge/dialog/select components (Tabler icons, not lucide)

actions/view-screen.ts

@@ -9,20 +9,34 @@
 
 import { defineAction } from "@agent-native/core/action";
 import { readAppState } from "@agent-native/core/application-state";
+import { eq } from "@agent-native/core/db/schema";
 import { z } from "zod";
 
+import { getDb } from "../server/db/index.js";
+import { stocks } from "../server/db/schema.js";
+
 export default defineAction({
   description:
     "See what the user is currently looking at on screen. Returns the current navigation state for the chat-first app. Always call this first before taking any action.",
   schema: z.object({}),
   http: false,
   readOnly: true,
-  run: async () => {
+  run: async (_args, ctx) => {
     const navigation = await readAppState("navigation");
 
     const screen: Record<string, unknown> = {};
     if (navigation) screen.navigation = navigation;
 
+    const view = (navigation as { view?: string } | null)?.view;
+    if (view === "stocks" && ctx?.userEmail) {
+      const db = getDb();
+      const rows = await db
+        .select()
+        .from(stocks)
+        .where(eq(stocks.ownerEmail, ctx.userEmail));
+      screen.stocks = { count: rows.length, listings: rows };
+    }
+
     if (Object.keys(screen).length === 0) {
       return "No application state found. Is the app running?";
     }