docs: Update Phase 0 with specific test fix requirements

Per ADR-012, Phase 0 now specifies:
- 5 tests to REMOVE (broken multiprocessing)
- 4 tests to FIX (brittle assertions)
- 1 test to RENAME (misleading name)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

starpunk/search.py

@@ -353,7 +353,7 @@ def search_notes_fts5(
                 'id': row['id'],
                 'slug': row['slug'],
                 'title': row['title'],
-                'snippet': Markup(row['snippet']),  # FTS5 snippet is safe
+                'snippet': row['snippet'],  # Plain string - route must escape HTML while preserving <mark> tags
                 'relevance': row['relevance'],
                 'published': bool(row['published']),
                 'created_at': row['created_at'],