First round of fixes surfaced by the anonymous usage telemetry (0.10.0):
- perf(dead-code): find_dead_code O(symbols x files) → O(1) token index (~18min → ~2s)
- fix(nest-audit): per-check timeout so one slow sub-check can't hang the audit (~17.5min tail)
- fix(hints): H2/H12 batch hints fire once instead of on every call (were emitted 100s of times, applied ~1.5%)
- fix(telemetry): capture plan_turn recommendations so the discovery funnel actually measures the router
- (impact_analysis WORKING/STAGED, find_and_show case-sensitivity, analyze_complexity budget already in 0.10.0)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>