feat: Vestige v1.7.0 — 18 tools, automation triggers, SQLite perf

Tool consolidation: 23 → 18 tools
- ingest merged into smart_ingest (single + batch mode)
- session_checkpoint merged into smart_ingest batch (items param)
- promote_memory/demote_memory merged into memory(action=promote/demote)
- health_check/stats merged into system_status

Automation triggers in system_status:
- lastDreamTimestamp, savesSinceLastDream, lastBackupTimestamp,
  lastConsolidationTimestamp — enables Claude to conditionally
  trigger dream/backup/gc/find_duplicates at session start
- Migration v6: dream_history table (dreams were in-memory only)
- DreamHistoryRecord struct + save/query methods
- Dream persistence in dream.rs (non-fatal on failure)

SQLite performance:
- PRAGMA mmap_size = 256MB (2-5x read speedup)
- PRAGMA journal_size_limit = 64MB (prevents WAL bloat)
- PRAGMA optimize = 0x10002 (fresh query planner stats on connect)
- FTS5 segment merge during consolidation (20-40% keyword boost)
- PRAGMA optimize during consolidation cycle

1,152 tests passing, 0 failures, release build clean.

scripts/xcode-setup.sh

@@ -254,7 +254,7 @@ echo "  Next steps:"
 echo "    1. Restart Xcode (Cmd+Q, then reopen)"
 echo "    2. Open your project"
 echo "    3. Type /context in the Agent panel"
-echo "    4. You should see vestige listed with 23 tools"
+echo "    4. You should see vestige listed with 18 tools"
 echo ""
 echo "  Try it:"
 echo "    \"Remember that this project uses SwiftUI with MVVM architecture\""