feat: add OpenTelemetry settings UI and sidecar environment wiring

Add a global Telemetry section in the settings panel with:
- Toggle to enable/disable OTLP export
- Text input for the OTLP endpoint URL (default: http://localhost:4317)
- Guidance note about using \un run aspire\ for local testing

Wire the setting through the full stack:
- OpenTelemetrySettings type in shared domain with normalization
- IPC channel, preload binding, and handler for persistence
- SidecarClient forwards settings to createSidecarEnvironment
- Sidecar environment injects OTEL_EXPORTER_OTLP_ENDPOINT when enabled
- Settings loaded from workspace.json on startup and on change

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

src/preload/index.ts

@@ -36,6 +36,7 @@ const api: ElectronApi = {
   setNotificationsEnabled: (enabled) => ipcRenderer.invoke(ipcChannels.setNotificationsEnabled, enabled),
   setMinimizeToTray: (enabled) => ipcRenderer.invoke(ipcChannels.setMinimizeToTray, enabled),
   setGitAutoRefreshEnabled: (enabled) => ipcRenderer.invoke(ipcChannels.setGitAutoRefreshEnabled, enabled),
+  setOpenTelemetry: (settings) => ipcRenderer.invoke(ipcChannels.setOpenTelemetry, settings),
   getQuickPromptSettings: () => ipcRenderer.invoke(ipcChannels.quickPromptGetSettings),
   setQuickPromptSettings: (settings) => ipcRenderer.invoke(ipcChannels.quickPromptSetSettings, settings),
   checkForUpdates: () => ipcRenderer.invoke(ipcChannels.checkForUpdates),