docs: add telemetry section to ARCHITECTURE.md and ABSTRACTIONS.md

Also adds Playwright smoke test for consent dialog and mock handler
for reinit_telemetry command.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docs/ABSTRACTIONS.md

@@ -589,3 +589,19 @@ interface Settings {
 ```
 
 Managed by `useSettings` hook and `SettingsPanel` component.
+
+## Telemetry
+
+### Components
+- **`TelemetryConsentDialog`** — First-launch dialog asking user to opt in to anonymous crash reporting. Two buttons: accept (sets `telemetry_consent: true`, generates `anonymous_id`) or decline.
+- **`TelemetryToggle`** — Checkbox component in `SettingsPanel` for crash reporting and analytics toggles.
+
+### Hooks
+- **`useTelemetry(settings, loaded)`** — Reactively initializes/tears down Sentry and PostHog based on settings. Called once in `App`.
+
+### Libraries
+- **`src/lib/telemetry.ts`** — `initSentry()`, `teardownSentry()`, `initPostHog()`, `teardownPostHog()`, `trackEvent()`. Path scrubber via `beforeSend` hook. DSN/key from `VITE_SENTRY_DSN` / `VITE_POSTHOG_KEY` env vars.
+- **`src-tauri/src/telemetry.rs`** — Rust-side Sentry init with `beforeSend` path scrubber. `init_sentry_from_settings()` reads settings and conditionally initializes. `reinit_sentry()` for runtime toggle.
+
+### Tauri Commands
+- **`reinit_telemetry`** — Re-reads settings and toggles Rust Sentry on/off. Called from frontend when user changes crash reporting setting.