chore(tier2): gitignore scripts/tier2/state/ and scripts/tier2/failures/

Track-isolated Tier 2 scratch dirs (per-track state.json + failure
reports). Excluding from git prevents accidental commits of run state
that would otherwise be tracked alongside the source.

Refs: conductor/tracks/tier2_no_appdata_20260618

.gitignore

@@ -9,6 +9,8 @@ credentials.toml
 uv.lock
 md_gen
 scripts/generated
+scripts/tier2/state/
+scripts/tier2/failures/
 logs
 logs/sessions/
 logs/agents/