chore: normalize to bun monorepo conventions

Applied monorepo normalization:
- Updated TypeScript to use composite project references with NodeNext
- Configured Biome for linting and formatting
- Standardized package.json metadata across all packages
- Set up changesets for version management and npm publishing
- Added vitest test infrastructure to all packages
- Created Gitea Actions CI pipeline
- Added solve-issue workflow

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

package.json

@@ -8,14 +8,20 @@
     "@biomejs/biome": "^2.0.0",
     "@changesets/changelog-github": "^0.7.0",
     "@changesets/cli": "^2.31.0",
+    "@types/node": "^22.0.0",
     "bun-types": "^1.3.14",
-    "typescript": "^5.8.0"
+    "typescript": "^5.8.0",
+    "vitest": "^4.1.7"
   },
   "scripts": {
-    "build": "tsc --build packages/json-cas packages/json-cas-fs",
-    "test": "bun test",
+    "build": "bunx tsc --build",
+    "typecheck": "bunx tsc --build",
+    "test": "bun run --filter './packages/*' test",
+    "test:ci": "bun run --filter './packages/*' test:ci",
     "check": "biome check .",
     "format": "biome format --write .",
-    "release": "changeset version && bun run build && changeset publish"
+    "changeset": "bunx changeset",
+    "version": "bunx changeset version",
+    "release": "bun run build && bun run test && node scripts/publish-all.mjs"
   }
 }