docs: Update CLAUDE.md with v0.5.0/v0.5.1 session history

- Added Prometheus metrics integration documentation
- Added localhost license bypass documentation
- Updated memory leak status to resolved (fixed in WP Prometheus)

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

CLAUDE.md

@@ -606,4 +606,55 @@ wp-fedistream/
 - WordPress hook system (class-wp-hook.php) can itself be the recursion point
 - The interaction between FediStream and WP Prometheus appears to be at a fundamental WordPress level
 
-**Status:** UNRESOLVED - Documented as known incompatibility, investigation to continue later
+**Status:** RESOLVED - Issue was fixed in WP Prometheus plugin, removed from known incompatibilities
+
+### 2026-02-02 - Prometheus Metrics & License Bypass v0.5.0/v0.5.1
+
+**Summary:** Added Prometheus metrics integration and localhost license bypass for development.
+
+**v0.5.0 - Prometheus Metrics Integration:**
+
+- Created `includes/Prometheus/Integration.php` with comprehensive metrics collection
+- Content metrics: `fedistream_content_total`, `fedistream_genres_total`, `fedistream_moods_total`
+- Engagement metrics: `fedistream_plays_total`, `fedistream_plays_today`, `fedistream_favorites_total`, `fedistream_local_follows_total`, `fedistream_listening_history_entries`
+- User metrics: `fedistream_users_with_library`, `fedistream_users_following_artists`, `fedistream_notifications_total`, `fedistream_notifications_pending`
+- WooCommerce metrics (conditional): `fedistream_purchases_total`, `fedistream_customers_total`, `fedistream_products_total`
+- ActivityPub metrics (conditional): `fedistream_activitypub_followers_total`, `fedistream_activitypub_followers_by_artist`, `fedistream_activitypub_reactions_total`
+- New setting in Integrations tab to enable/disable
+- Uses `wp_prometheus_collect_metrics` action hook
+
+**v0.5.1 - Localhost License Bypass:**
+
+- Added `is_localhost()` method to License Manager
+- Bypasses license check on: `localhost`, `127.0.0.1`, `::1`
+- Also bypasses for TLDs: `.local`, `.test`, `.localhost`, `.dev.local`
+- Allows full plugin functionality during local development
+
+**Files Created:**
+
+- `includes/Prometheus/Integration.php` - Metrics collection class
+- `includes/Prometheus/index.php` - Security file
+
+**Files Modified:**
+
+- `includes/Plugin.php` - Added Prometheus integration, settings toggle, `is_prometheus_active()` method
+- `includes/Installer.php` - Added `wp_fedistream_enable_prometheus` default option
+- `includes/License/Manager.php` - Added `is_localhost()` method, bypass in `is_license_valid()`
+- `README.md` - Removed known incompatibility section, updated version badge
+
+**Integration Pattern:**
+
+Follows same pattern as WooCommerce/ActivityPub integrations:
+
+```php
+if (get_option('wp_fedistream_enable_prometheus', 0) && $this->is_prometheus_active()) {
+    new PrometheusIntegration();
+}
+```
+
+**Notes:**
+
+- WP Prometheus memory leak issue was fixed in WP Prometheus itself
+- Metrics use simple COUNT queries for performance
+- ActivityPub followers limited to top 10 to avoid cardinality explosion
+- Default disabled (opt-in via Settings > Integrations)