Generate and check Platform route types independently

Author: emir-karabeg

apps/sim/package.json

@@ -11,6 +11,7 @@
     "dev": "bun run build:cli-runtime && bun run dev:cache:cap && next dev --port 3000",
     "dev:platform": "cd platform && next dev --webpack --port 3100",
     "build:platform": "cd platform && next build --webpack",
+    "type-check:platform": "cd platform && next typegen && tsc --noEmit",
     "test:platform:desktop": "playwright test --config platform/checks/desktop/playwright.config.ts",
     "test:platform:e2e": "playwright test --config platform/checks/playwright.config.ts",
     "start:platform": "cd platform && next start --port 3100",
@@ -41,7 +42,7 @@
     "test:watch": "vitest",
     "test:coverage": "vitest run --coverage",
     "email:dev": "email dev --dir components/emails",
-    "type-check": "tsc --noEmit",
+    "type-check": "tsc --noEmit && bun run type-check:platform",
     "lint": "biome check --write --unsafe .",
     "lint:check": "biome check .",
     "format": "biome format --write .",

apps/sim/platform/README.md

@@ -57,6 +57,7 @@ The [Platform design contract](AGENTS.md) is authoritative. Use the repository's
 
 ```sh
 bun run check:platform-design
+bun run --cwd apps/sim type-check:platform
 bun run --cwd apps/sim build:platform
 bunx --no-install playwright install chromium
 bun run --cwd apps/sim test:platform:e2e
@@ -65,6 +66,8 @@ bun run --cwd apps/desktop build
 bun run --cwd apps/sim test:platform:desktop
 ```
 
+The Platform type check generates Next.js route types and checks the isolated project. The repository type check runs it alongside the existing app’s TypeScript project.
+
 The browser suite starts separate production servers with fixtures enabled and disabled. Supply `PLATFORM_REPORT_PATH` to save JSON, failure screenshots and traces. Next uses webpack for this nested app: the installed Turbopack also discovers the parent Sim project's proxy and instrumentation. Watch for that boundary when upgrading Next.
 
 The static check covers ownership, styling props, evidence, tokens, code usage and dependency direction. It cannot establish that a browser rendering matches Paper. Compare both themes, keyboard and pointer states, actual overflow, text scaling and widths between approved artboards. Build the standalone app before running the browser suite to test the current sources.

apps/sim/tsconfig.json

@@ -32,6 +32,7 @@
   "exclude": [
     "node_modules",
     ".next",
+    "platform",
     "**/*.test.ts",
     "**/*.test.tsx",
     "vitest.config.ts",