feat(telemetry): add OpenTelemetry tracing with optional OTLP export to Tempo

v2/src/lib/adapters/telemetry-bridge.ts

@@ -0,0 +1,26 @@
+// Telemetry bridge — routes frontend events to Rust tracing via IPC
+// No browser OTEL SDK needed (WebKit2GTK incompatible)
+
+import { invoke } from '@tauri-apps/api/core';
+
+type LogLevel = 'error' | 'warn' | 'info' | 'debug' | 'trace';
+
+/** Emit a structured log event to the Rust tracing layer */
+export function telemetryLog(
+  level: LogLevel,
+  message: string,
+  context?: Record<string, unknown>,
+): void {
+  invoke('frontend_log', { level, message, context: context ?? null }).catch(() => {
+    // Swallow IPC errors — telemetry must never break the app
+  });
+}
+
+/** Convenience wrappers */
+export const tel = {
+  error: (msg: string, ctx?: Record<string, unknown>) => telemetryLog('error', msg, ctx),
+  warn: (msg: string, ctx?: Record<string, unknown>) => telemetryLog('warn', msg, ctx),
+  info: (msg: string, ctx?: Record<string, unknown>) => telemetryLog('info', msg, ctx),
+  debug: (msg: string, ctx?: Record<string, unknown>) => telemetryLog('debug', msg, ctx),
+  trace: (msg: string, ctx?: Record<string, unknown>) => telemetryLog('trace', msg, ctx),
+};