style: Implement High-Contrast Minimalism UI & feat: Hybrid Search (FTS5 BM25) ...

- Refactored UI to follow minimalist HUD design spec.
- Replaced LSA-only search with Hybrid Search (Vector + FTS5 BM25).
- Integrated trigram tokenizer for robust Japanese keyword matching.
- Fixed MCP activity log rendering issues.
- Updated documentation and added MIT LICENSE.
- Updated work journal.

docs: remove Japanese duplicate journal (keep ASCII copy)

UI: stabilize header/footer layout (left-aligned); remove panel borders; move brand out of search panel; add journal

Refactor: reorganization of root and source directories and fix Error 1412