# P0 Product-Level Metrics and Dashboard

## Module
Telemetry

## Status
IMPLEMENTED

## Description
Four P0 product-level metrics instrumented: time-to-first-verified-release, mean-time-to-answer-why-blocked, support-minutes-per-customer, and determinism-regressions-total, with Prometheus alerting rules and install timestamp tracking service.

## Implementation Details
- **P0ProductMetrics**: `src/Telemetry/StellaOps.Telemetry.Core/StellaOps.Telemetry.Core/P0ProductMetrics.cs` -- meter `StellaOps.P0Metrics` with 4 P0 metrics:
  - P0M-001: `stella_time_to_first_verified_release_seconds` -- histogram with buckets 5m to 1 week
  - P0M-002: `stella_why_blocked_latency_seconds` -- mean time to answer "why blocked"
  - P0M-003: `stella_support_burden_minutes_total` -- support minutes per customer counter
  - P0M-004: `stella_determinism_regressions_total` -- determinism regression counter
- **InstallTimestampService**: `src/Telemetry/StellaOps.Telemetry.Core/StellaOps.Telemetry.Core/InstallTimestampService.cs` -- tracks fresh install timestamp for P0M-001
- **GoldenSignalMetrics**: `src/Telemetry/StellaOps.Telemetry.Core/StellaOps.Telemetry.Core/GoldenSignalMetrics.cs` -- golden signal metrics (latency, traffic, errors, saturation)
- **FidelityMetricsTelemetry**: `src/Telemetry/StellaOps.Telemetry.Core/StellaOps.Telemetry.Core/FidelityMetricsTelemetry.cs` -- fidelity metrics for evidence quality
- **FidelitySloAlertingService**: `src/Telemetry/StellaOps.Telemetry.Core/StellaOps.Telemetry.Core/FidelitySloAlertingService.cs` -- SLO alerting for fidelity metrics
- **ProofCoverageMetrics**: `src/Telemetry/StellaOps.Telemetry.Core/StellaOps.Telemetry.Core/ProofCoverageMetrics.cs` -- proof coverage tracking
- **ProofGenerationMetrics**: `src/Telemetry/StellaOps.Telemetry.Core/StellaOps.Telemetry.Core/ProofGenerationMetrics.cs` -- proof generation performance
- **Tests**: `src/Telemetry/StellaOps.Telemetry.Core/StellaOps.Telemetry.Core.Tests/GoldenSignalMetricsTests.cs`, `ProofCoverageMetricsTests.cs`
- **Source**: SPRINT_20260117_028_Telemetry

## E2E Test Plan
- [ ] Verify time-to-first-verified-release histogram records elapsed time from install
- [ ] Test why-blocked latency captures mean time from block to explanation delivery
- [ ] Verify support minutes counter increments per customer interaction
- [ ] Test determinism regression counter fires on replay divergence detection
- [ ] Verify Prometheus alerting rules trigger on SLO breaches
- [ ] Test install timestamp service persists and recovers install time across restarts