fix: Phase 2 integrity review - v2.0.0 rewrite & bugfixes

Memory Consolidation Plugin (828 -> 465 lines):
- Replace SentenceTransformer with cat.embedder.embed_query() for vector consistency
- Fix per-user fact isolation: source=user_id instead of global
- Add duplicate fact detection (_is_duplicate_fact, score_threshold=0.85)
- Remove ~350 lines of dead async run_consolidation() code
- Remove duplicate declarative search in before_cat_sends_message
- Unify trivial patterns into TRIVIAL_PATTERNS frozenset
- Remove all sys.stderr.write debug logging
- Remove sentence-transformers from requirements.txt (no external deps)

Loguru Fix (cheshire-cat/cat/log.py):
- Patch Cat v1.6.2 loguru format to provide default extra fields
- Fixes KeyError: 'original_name' from third-party libs (fastembed)
- Mounted via docker-compose volume

Discord Bridge:
- Copy discord_bridge.py to cat-plugins/ (was empty directory)

Test Results (6/7 pass, 100% fact recall):
- 11 facts extracted, per-user isolation working
- Duplicate detection effective (+2 on 2nd run)
- 5/5 natural language recall queries correct

cat-plugins/memory_consolidation/requirements.txt

@@ -1 +0,0 @@
-sentence-transformers>=2.2.0