fix(FN-3433): restore workspace llama-cpp docs index integrity

- Restore workspace llama-cpp extension path resolution in CLI command handling
- Add missing docs/README.md index entries and keep README/doc links aligned
- Add regression coverage for docs README index completeness and docker docs references
- Carry forward related workspace stability updates and test hardening from the branch

Fusion-Task-Id: FN-3433

packages/engine/package.json

@@ -37,8 +37,8 @@
   "dependencies": {
     "@fusion/core": "workspace:*",
     "@fusion/pi-claude-cli": "workspace:*",
-    "@mariozechner/pi-ai": "^0.72.1",
-    "@mariozechner/pi-coding-agent": "^0.72.1",
+    "@mariozechner/pi-ai": "^0.73.0",
+    "@mariozechner/pi-coding-agent": "^0.73.0",
     "typebox": "^1.0.0",
     "cron-parser": "^5.5.0"
   },