Update CLAUDE.md with v0.7.4 session learnings

- Removed v0.7.4 from roadmap (completed)
- Added session history for Prometheus metrics integration
- Documented new PrometheusController and metrics implementation

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

CLAUDE.md

@@ -1990,3 +1990,44 @@ Added `ResponseSigner::getServerSecret()` static method that checks multiple sou
 - The fix maintains backward compatibility with standard WordPress installations using constants
 - Docker environments can now use environment variables directly without needing the constant to be defined
 - All three methods (`isSigningEnabled()`, `getCustomerSecretForLicense()`, and constructor) now use the centralized `getServerSecret()` method
+
+### 2026-02-03 - Version 0.7.4 - Prometheus Metrics Integration
+
+**Overview:**
+
+Added Prometheus metrics integration to expose license and API metrics for monitoring. Requires the WP Prometheus plugin.
+
+**New files:**
+
+- `src/Metrics/PrometheusController.php` - Prometheus metrics collection controller
+
+**Implemented:**
+
+- New "Metrics" settings section with enable/disable toggle
+- Hooks into `wp_prometheus_collect_metrics` action for metric collection
+- License gauges using existing `LicenseManager::getStatistics()`:
+  - `wclp_licenses_total{status}` - License counts by status
+  - `wclp_licenses_lifetime_total` - Lifetime licenses count
+  - `wclp_licenses_expiring_total` - Expiring licenses count
+  - `wclp_licenses_expiring_soon` - Licenses expiring within 30 days
+- Download gauges using existing `VersionManager::getDownloadStatistics()`:
+  - `wclp_downloads_total` - Total downloads
+  - `wclp_versions_active_total` - Active product versions
+- API counters (stored in WordPress options for persistence):
+  - `wclp_api_requests_total{endpoint,result}` - API requests by endpoint and result
+  - `wclp_rate_limit_exceeded_total{endpoint}` - Rate limit exceeded events
+  - `wclp_validation_errors_total{error_type}` - Validation errors by type
+
+**Modified files:**
+
+- `src/Admin/SettingsController.php` - Added 'metrics' section with settings
+- `src/Api/RestApiController.php` - Added metric tracking for API requests
+- `src/Api/UpdateController.php` - Added metric tracking for update-check requests
+- `src/Plugin.php` - Initialize PrometheusController
+
+**Technical notes:**
+
+- Metrics are only collected when enabled via settings toggle
+- Static methods allow increment from API controllers without dependency injection
+- Counter values persist across requests via `wclp_prometheus_counters` option
+- Gauges query database on each metric collection (uses existing statistics methods)