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/analytics.ts

@@ -1,8 +1,11 @@
 import { invoke } from "@tauri-apps/api/core";
+import { telemetryLog } from "./telemetry";
 
 export type AnalyticsEventProperties = Record<string, string | number>;
 
 export function trackAnalyticsEvent(name: string, props?: AnalyticsEventProperties) {
+  const details = props && Object.keys(props).length > 0 ? ` ${JSON.stringify(props)}` : "";
+  telemetryLog("info", `${name}${details}`, `product.${name}`);
   void invoke("plugin:aptabase|track_event", {
     name,
     props: props && Object.keys(props).length > 0 ? props : undefined,

src/lib/components/AnalyticsNoticeDialog.svelte

@@ -30,10 +30,10 @@
       </div>
       <div class="analytics-notice-copy">
         <p>
-          Gitty can send anonymous usage events to Aptabase so crashes, rough edges, and commonly used workflows are easier to improve.
+          Gitty can send anonymous usage events and technical error logs to Aptabase and the self-hosted SigNoz service so crashes, rough edges, and commonly used workflows are easier to improve.
         </p>
         <p>
-          Events do not include repository paths, remote URLs, branch names, commit messages, diffs, file names, credentials, or source code.
+          Telemetry does not include repository paths, remote URLs, branch names, commit messages, diffs, file names, credentials, or source code.
         </p>
       </div>
 
@@ -47,7 +47,7 @@
     </div>
 
     <footer class="dialog-footer analytics-notice-footer">
-      <span class="dialog-footer-info">Privacy-friendly, optional, and limited to product usage events.</span>
+      <span class="dialog-footer-info">Privacy-friendly, optional, and limited to product usage and technical errors.</span>
       <button class="btn-primary" type="button" onclick={() => onContinue(allowAnalytics)}>
         <Check size={16} aria-hidden="true" />
         Continue

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>

src/lib/git.ts

@@ -1,4 +1,4 @@
-import { invoke } from "@tauri-apps/api/core";
+import { tracedInvoke as invoke } from "./telemetry";
 
 import type {
   AiReviewResult,

src/lib/telemetry.ts

@@ -0,0 +1,72 @@
+import { invoke } from "@tauri-apps/api/core";
+
+type TelemetryLevel = "info" | "warn" | "error";
+
+const MAX_MESSAGE_LENGTH = 2_048;
+let telemetryEnabled = false;
+let configuration: Promise<unknown> = Promise.resolve();
+
+// Telemetry must never contain repository contents or identifying local data.
+function sanitize(message: string): string {
+  return message
+    .replace(/https?:\/\/\S+/gi, "[url]")
+    .replace(/(?:[A-Za-z]:\\|\/)(?:[^\s<>:"|?*]+[\\/])*[^\s<>:"|?*]*/g, "[path]")
+    .replace(/(token|password|secret|authorization|credential)\s*[:=]\s*\S+/gi, "$1=[redacted]")
+    .replace(/[\w.+-]+@[\w.-]+\.[A-Za-z]{2,}/g, "[email]")
+    .slice(0, MAX_MESSAGE_LENGTH);
+}
+
+export function setTelemetryEnabled(enabled: boolean) {
+  telemetryEnabled = enabled;
+  configuration = invoke("set_telemetry_enabled", { enabled }).catch(() => {});
+}
+
+export function telemetryLog(level: TelemetryLevel, message: string, eventName?: string) {
+  if (!telemetryEnabled) return;
+  void configuration.then(() => invoke("emit_frontend_log", {
+      log: {
+        level,
+        message: sanitize(message),
+        eventName,
+      },
+    }))
+    .catch(() => {
+      // Observability must never interrupt the Git workflow.
+    });
+}
+
+function randomHex(bytes: number): string {
+  const values = new Uint8Array(bytes);
+  crypto.getRandomValues(values);
+  return Array.from(values, (value) => value.toString(16).padStart(2, "0")).join("");
+}
+
+export async function tracedInvoke<T>(command: string, args?: Record<string, unknown>): Promise<T> {
+  if (!telemetryEnabled) return invoke<T>(command, args);
+  const startedAtMs = Date.now();
+  const started = performance.now();
+  const traceId = randomHex(16);
+  const spanId = randomHex(8);
+  try {
+    const result = await invoke<T>(command, args);
+    void configuration.then(() => invoke("emit_frontend_span", {
+      span: { name: command, traceId, spanId, startedAtMs, durationMs: performance.now() - started, success: true },
+    })).catch(() => {});
+    return result;
+  } catch (error) {
+    void configuration.then(() => invoke("emit_frontend_span", {
+      span: { name: command, traceId, spanId, startedAtMs, durationMs: performance.now() - started, success: false },
+    })).catch(() => {});
+    throw error;
+  }
+}
+
+export function installGlobalErrorTelemetry() {
+  window.addEventListener("error", (event) => {
+    telemetryLog("error", event.message || "Unhandled frontend error", "frontend.unhandled_error");
+  });
+  window.addEventListener("unhandledrejection", (event) => {
+    const message = event.reason instanceof Error ? event.reason.message : String(event.reason ?? "Unhandled promise rejection");
+    telemetryLog("error", message, "frontend.unhandled_rejection");
+  });
+}