docs(phase-01): evolve PROJECT.md after phase completion

.planning/PROJECT.md

@@ -12,7 +12,10 @@ Detect leaked LLM API keys across more providers and more internet sources than
 
 ### Validated
 
-(None yet — ship to validate)
+- ✓ Core scanning engine (regex + entropy + keyword pre-filtering) — Phase 1
+- ✓ Plugin-based architecture — providers as YAML, compile-time embedded — Phase 1
+- ✓ SQLite storage with AES-256 encryption — Phase 1
+- ✓ CLI with Cobra: scan, providers, config commands — Phase 1
 
 ### Active
 
@@ -111,4 +114,4 @@ This document evolves at phase transitions and milestone boundaries.
 4. Update Context with current state
 
 ---
-*Last updated: 2026-04-04 after initialization*
+*Last updated: 2026-04-05 after Phase 1 completion*