fix: resolve tool error counting logic and add advanced UI execution metrics

feat(agents): full implementation of harness engineering and file sync fixes ...

- Implemented Area 1: Backend scaffolding, CRUD, schemas, and session locking
- Implemented Area 2: Agent execution loop, RAG integration, and Circuit Breaker
- Updated UI: Configure CRON triggers, Target Mesh nodes, and display system prompt in Agent Drilldown
- Fixed LLM fallback resolving vertex_ai_beta
- Fixed File System Sync pseudo-nodes (hub, local) raising 'Offline'
- Fixed FileSystemNavigator initialPath bug causing synced files not to render in UI Mesh Workspace

fix(tool_service): fix LazyFileContent property indentation bug causing NoneType error

Fix frontend build crash by updating getNodes to getUserAccessibleNodes and restore production service sync

feat/fix: Rich token usage popovers, robust LiteLLM context window bounds logic, and Skill management refactor

feat(auth): bootstrap Day 1 local auth fallback, migrations, and sandbox node

Refactor backend code to improve modularity and extensibility