chore: align sqlite control plane architecture

- replace default Convex control-plane wording with Rust SQLite control-plane across architecture, AGENTS, Reasonix, and design docs

- retire root Convex functions source and deploy script into recycle while keeping explicit cloud/compat/sync-replica boundaries

- add control-plane migration guard/docs and keep CodeGraph refreshed after the SQLite control-plane cutover

package.json

@@ -8,13 +8,8 @@
     "dev:hot": "node scripts/dev-hot.js",
     "check:local-first-convex-guard": "node scripts/check-local-first-convex-guard.js"
   },
-  "dependencies": {
-    "@auth/core": "0.37.0",
-    "@convex-dev/auth": "0.0.91"
-  },
   "devDependencies": {
     "@playwright/test": "^1.56.1",
-    "convex": "^1.39.1",
     "playwright": "^1.56.1"
   }
 }