Replace void returns with { success: true } across all API endpoints

- Add successResponseSchema to common.ts for explicit success responses
- Update all auth, me, orgs, and admin procedures to return { success: true }
- Update contract.ts to use successResponseSchema instead of z.void()
- Add ast-grep rule to prevent future z.void() usage in contracts
- Add build:packages script to root package.json
- Fix test file lint errors with eslint-disable comments

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

package.json

@@ -10,6 +10,7 @@
     "dev": "turbo dev",
     "build": "turbo build",
     "build:watch:packages": "turbo watch build --filter=./packages/*",
+    "build:packages": "turbo build --filter=./packages/*",
     "lint": "biome check && turbo run lint",
     "lint:fix": "biome check --write --unsafe && turbo run lint -- --fix",
     "typecheck": "turbo typecheck",