feat: enhance observability with Sentry integration and logging improvements

- Added Sentry DSNs to .env.example for error and log forwarding configuration.
- Integrated Sentry logging capabilities in the logger module to capture and forward logs based on defined log levels.
- Updated Header component to include a manual Sentry test button for client-side error tracking.
- Enhanced worker logging to utilize the new logger, providing better insights into job processing and errors.
- Updated vars.example.yml to include new Sentry logging configurations for improved observability.

Author: regenrek

.env.example

@@ -41,6 +41,22 @@ VITE_POLAR_PRODUCT_CREDITS_100="prod_..."
 VITE_POLAR_PRODUCT_PRO_MONTHLY="prod_..."
 VITE_POLAR_PRODUCT_BUSINESS_MONTHLY="prod_..."
 
+# =============================================================================
+# OBSERVABILITY / SENTRY
+# =============================================================================
+# Supply Sentry DSNs to enable error + log forwarding. Leave empty to disable.
+SENTRY_DSN=""
+VITE_SENTRY_DSN=""
+
+# Structured logging fan-out. Flip these to control console patching and
+# whether application logs sync to Sentry.
+SENTRY_LOGGING="true"
+VITE_SENTRY_LOGGING="true"
+SENTRY_LOG_LEVEL="warn"
+VITE_SENTRY_LOG_LEVEL="warn"
+CONSOLE_LOGGER_PATCH="true"
+VITE_CONSOLE_LOGGER_PATCH="true"
+
 # =============================================================================
 # DATABASE CONFIGURATION
 # =============================================================================