feat: Implement telemetry for reconnect reasons and RTT reporting

- Added telemetry hooks to track reconnect reasons for WireGuard connections, including server requests and authentication errors.
- Introduced RTT reporting to telemetry for better latency monitoring.
- Enhanced metrics configuration with flags for Prometheus and OTLP exporters.
- Implemented graceful shutdown and signal handling in the main application.
- Updated WebSocket client to classify connection errors and report them to telemetry.
- Added support for async byte counting in metrics.
- Improved handling of reconnect scenarios in the WireGuard service.
- Added documentation for applying patches and rollback procedures.

patches/HOWTO-APPLY.md

@@ -0,0 +1,25 @@
+# How to apply patches
+
+These patches were generated from the working tree without commits. You can apply them in one shot or in topic order.
+
+One shot (recommended during review):
+
+```bash
+git apply patches/00_all_changes.patch
+```
+
+Topic order:
+
+```bash
+git apply patches/01_proxy_multitunnel.patch
+git apply patches/02_reconnect_rtt.patch
+git apply patches/03_constants_docs.patch
+```
+
+Rollback (restore to HEAD and clean untracked files):
+
+```bash
+git restore --source=HEAD --worktree --staged .
+git clean -fd
+```
+