## Parent epic: #2141 ## Phase 5: Metrics + TUI + observability ### Tasks - New metrics: `triage_latency_ms` (histogram), `triage_tier` (counter per tier), `triage_escalation_rate`, `triage_cost_saved_cents` - TUI status bar: show current tier during inference ("Tier: Complex → claude-sonnet") - Debug dump: include `TriageVerdict` in session dump (tier, reason, latency_ms) - `/triage` slash command: show triage stats (calls, tier distribution, avg latency, estimated savings) ### Key files - `crates/zeph-core/src/agent/mod.rs` (metrics recording) - `crates/zeph-tui/src/` (status bar indicator) - `crates/zeph-core/src/agent/slash_commands.rs` (`/triage` command) ### Acceptance criteria - Triage latency tracked per call - TUI shows tier during active inference - Debug dump contains triage verdict
