feat(telemetry): Implement structured telemetry logging and reporting

Adds comprehensive client-side telemetry capabilities for usage, errors, and performance metrics. This includes integrating OpenTelemetry standards into both the frontend (Svelte) and backend (Tauri/Rust) layers to capture events, spans, and system resource utilization.

The implementation ensures that all collected data is privacy-filtered by design, explicitly excluding sensitive information like repository paths, credentials, source code, or email addresses from being logged.

- Updates README with detailed SigNoz telemetry guide
- Adds process metrics collection (CPU/Memory) in Rust backend
- Exposes `setTelemetryEnabled` state management to the frontend

src/lib/components/AppSettingsDialog.svelte

@@ -124,7 +124,7 @@
         <label class="settings-toggle-row">
           <input type="checkbox" bind:checked={analyticsEnabled} />
           <span>
-            <strong>{isGerman ? "Anonyme Aptabase-Ereignisse erlauben" : "Allow anonymous Aptabase events"}</strong>
+            <strong>{isGerman ? "Anonyme Analytics und Fehlerberichte erlauben" : "Allow anonymous analytics and error reports"}</strong>
             <small>{isGerman ? "Es werden keine Repository-Pfade, Remotes, Branches, Commit-Nachrichten, Dateinamen, Diffs, Zugangsdaten oder Code übertragen." : "No repository paths, remotes, branches, commit messages, file names, diffs, credentials, or code are sent."}</small>
           </span>
         </label>