feat: complete TUI Phase 0 — Toolchain Gate

Implements the full lore-tui crate scaffold with 6 Phase 0 modules:

- message.rs: Msg (~40 variants), Screen (12), EntityKey, AppError, InputMode
- clock.rs: Clock trait with SystemClock + FakeClock for deterministic testing
- safety.rs: Terminal sanitizer (ANSI filter), URL policy, PII/secret redaction
- db.rs: DbManager with 3 reader pool (round-robin) + dedicated writer (WAL mode)
- theme.rs: Flexoki adaptive theme (19 slots), state/event colors, label styling
- app.rs: Minimal LoreApp Model trait impl proving FrankenTUI integration

68 tests, clippy clean, fmt clean. Closes bd-3ddw, bd-c9gk, bd-2lg6,
bd-3ir1, bd-2kop, bd-5ofk, bd-2emv, bd-1cj0.

.gitignore

@@ -1,11 +1,6 @@
-# Dependencies
-node_modules/
-
-# Build output
-dist/
-
-# Test coverage
-coverage/
+# Rust build output
+/target
+**/target/
 
 # IDE
 .idea/
@@ -25,14 +20,11 @@ Thumbs.db
 
 # Logs
 *.log
-npm-debug.log*
-yarn-debug.log*
-yarn-error.log*
 
 # Local config files
 lore.config.json
 
-# beads
+# beads viewer cache
 .bv/
 
 # SQLite databases (local development)
@@ -40,7 +32,8 @@ lore.config.json
 *.db-wal
 *.db-shm
 
-
-# Added by cargo
-
-/target
+# Profiling / benchmarks
+perf.data
+perf.data.old
+flamegraph.svg
+*.profraw