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/App.svelte

@@ -1,7 +1,6 @@
 <script lang="ts">
   import { onDestroy, onMount, tick } from "svelte";
   import { getVersion } from "@tauri-apps/api/app";
-  import { invoke } from "@tauri-apps/api/core";
   import { open as openDialog } from "@tauri-apps/plugin-dialog";
   import { check, type DownloadEvent, type Update } from "@tauri-apps/plugin-updater";
   import { AlertCircle, Cherry, Download, FolderOpen, GitBranch, GitMerge, LoaderCircle, Plus, Search, Star, X } from "@lucide/svelte";
@@ -160,6 +159,7 @@
     summarizeGitError,
   } from "./lib/credentials";
   import { trackAnalyticsEvent, type AnalyticsEventProperties } from "./lib/analytics";
+  import { setTelemetryEnabled, tracedInvoke } from "./lib/telemetry";
 
   type UpdateToastState = "available" | "downloading" | "installed" | "error";
   type AppView = "management" | "repository";
@@ -503,7 +503,7 @@
 
   async function closeStartupSplashscreen() {
     try {
-      await invoke("close_splashscreen");
+      await tracedInvoke("close_splashscreen");
     } catch {
       // Browser preview and failed startup paths should keep working without Tauri.
     }
@@ -815,6 +815,7 @@
 
   function initAnalytics() {
     analyticsSettings = loadAnalyticsSettings();
+    setTelemetryEnabled(analyticsSettings.noticeSeen && analyticsSettings.enabled);
     if (!analyticsSettings.noticeSeen) {
       analyticsNoticeOpen = true;
       return;
@@ -831,6 +832,7 @@
     analyticsSettings = { enabled, noticeSeen: true };
     persistAnalyticsSettings(analyticsSettings);
     analyticsNoticeOpen = false;
+    setTelemetryEnabled(enabled);
     trackEvent("app_started", { first_run: 1 });
   }
 
@@ -900,6 +902,7 @@
     persistThemePreference(nextTheme);
     persistLanguagePreference(nextLanguage);
     persistStoredBoolean(AUTO_REFRESH_ENABLED_KEY, nextAutoRefresh);
+    setTelemetryEnabled(next.enabled);
     appSettingsOpen = false;
     if (nextAutoRefresh && !autoRefreshWasEnabled) void autoRefreshTick();
     if (next.enabled) trackEvent("settings_saved", { analytics_enabled: 1, theme: nextTheme, language: nextLanguage, auto_refresh: nextAutoRefresh ? 1 : 0 });
@@ -1746,9 +1749,11 @@
   }
 
   function errorToMessage(error: unknown): string {
-    if (error instanceof Error) return error.message;
-    if (typeof error === "string") return error;
-    try { return JSON.stringify(error) ?? "Unknown error"; } catch { return "Unknown error"; }
+    let message: string;
+    if (error instanceof Error) message = error.message;
+    else if (typeof error === "string") message = error;
+    else try { message = JSON.stringify(error) ?? "Unknown error"; } catch { message = "Unknown error"; }
+    return message;
   }
 
   function isNonFastForwardPushError(message: string): boolean {