chore: migrate from bun to pnpm + vitest + esbuild

- Replace bun:test with vitest across all packages
- Replace bun build with esbuild
- Replace bun:sqlite with better-sqlite3
- Fix OCAS Store API: store.put/get → store.cas.put/get
- Fix vitest vi.mock hoisting (vi.hoisted)
- Add pnpm-workspace.yaml and pnpm-lock.yaml
- Update all package.json test/build scripts

WIP: 8 failures remain in agent-hermes (bun engines check + sqlite migration)

Refs #26

packages/dashboard/tsconfig.json

@@ -13,7 +13,7 @@
     "resolveJsonModule": true,
     "isolatedModules": true,
     "noEmit": true,
-    "types": ["bun-types"],
+    "types": ["node"],
     "paths": {
       "@/*": ["./src/*"]
     }