docs(performance): scope dev-mode counts and list the recording heartbeat

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/architecture/idle-work-audit-2026-09.md

@@ -59,8 +59,11 @@ The three worst offenders, in order:
 - **Build.** `pnpm nx run electron-backend:build-e2e` on `8ebb7e342`. It
   is unoptimized, with source maps and Angular dev mode. Dev mode runs every
   change detection twice (the `checkNoChanges` pass), so per-firing
-  renderer costs below are upper bounds for a production build. Counts are
-  exact either way.
+  renderer costs below are upper bounds for a production build. Timer, rAF,
+  IPC, SQL, HTTP, layout and DOM-mutation counts do not depend on dev mode.
+  The Angular change-detection and template-update counts are dev-build
+  counts: a production build skips the `checkNoChanges` pass, so it performs
+  fewer template updates per tick.
 - **Servers.** The Xtream mock ran on loopback port 3411 with its control
   plane enabled. A second E2E worktree already held 3310. A throwaway loopback
   HTTP server served a 60-channel M3U with `url-tvg` and logo URLs, and it
@@ -211,6 +214,7 @@ user who leaves that screen open pays them indefinitely, minimized included.
 | [embedded-mpv-native.service.ts:1068](../../apps/electron-backend/src/app/services/embedded-mpv-native.service.ts) | Embedded MPV session snapshot poll | 500 ms while a session exists | Native snapshot, diff, and IPC only on change | Yes during playback. It is cleared when the last session closes. | Static | None |
 | [embedded-mpv-session-controller.ts:197](../../libs/ui/playback/src/lib/embedded-mpv-player/embedded-mpv-session-controller.ts) | Renderer-side bounds poll for a native-view embedded MPV session: compares `getBoundingClientRect()` with the last synced bounds | 500 ms while a native-view session is open (skipped for frame-copy) | One layout read outside the Angular zone; on drift a rAF and a `setEmbeddedMpvBounds` IPC | Yes during playback: a position-only layout shift would otherwise leave the native view misplaced | Static | Cover with the throttling thread: it kept its rate while minimized under `backgroundThrottling: false`. |
 | [embedded-mpv-frame-pump.ts:212](../../apps/electron-backend/src/app/api/embedded-mpv-frame-pump.ts) (preload) | Frame-copy engine's frame pump: `pumpTick` re-arms itself with `requestAnimationFrame`, checks the shared-memory ring for a new frame, and uploads and draws it when one arrived | Every display frame while a frame-copy session is attached, paused included; stops only on detach. Opt-in (`IPTVNATOR_ENABLE_EMBEDDED_MPV_FRAME_COPY`) | A ring read per frame; a texture upload and draw per new frame | Yes while the video is on screen. A paused or minimized session gains nothing from 60 Hz polling. | Static. Under `backgroundThrottling: false`, rAF kept firing in a minimized window: the E2E fixture's own rAF counter ran at 60 Hz there. | Cover with the throttling thread (rAF stops in a hidden window once throttling is on), and consider stopping the pump while paused. |
+| [embedded-mpv-controls.adapter.ts:252](../../libs/ui/playback/src/lib/embedded-mpv-player/embedded-mpv-controls.adapter.ts) (frame-copy) and [embedded-mpv-player.component.ts:587](../../libs/ui/playback/src/lib/embedded-mpv-player/embedded-mpv-player.component.ts) (native view) | Elapsed-time heartbeat of an active embedded-MPV recording; the two intervals are mutually exclusive by engine | 1 s while a recording is active | A signal write and a CD tick | Yes while the elapsed time is on screen. A minimized window gains nothing from it. | Static. Under `backgroundThrottling: false` it kept its rate while minimized. | Cover with the throttling thread (throttled while hidden once #1724 lands). |
 | [embedded-mpv-reconnect.ts:296](../../apps/electron-backend/src/app/services/embedded-mpv-reconnect.ts) | Reconnect backoff | 2 s to 30 s, at most 6 attempts | Native reload | Yes | Static | None |
 | [channel-list-container.component.ts:426, :431](../../libs/ui/components/src/lib/channel-list-container/channel-list-container.component.ts) | M3U list: re-queries current programmes and metadata for **all** channels in the list, plus a progress tick | 60 s / 30 s while an M3U list is mounted | IPC and SQL that grow with channel count (not measured) | **Partly.** Only visible rows need refreshing. | Static | **Own thread.** Measure on a 10k-channel list, then limit to the viewport and pause on hidden. |
 | [epg-refresh-coordinator.service.ts:82](../../libs/portal/xtream/feature/src/lib/portal-channels-list/epg-refresh-coordinator.service.ts) | Xtream live: refreshes stale visible or tracked EPG entries | 60 s while live lists are registered | Xtream HTTP through main for stale entries only | Yes (already scoped) | Static | Pause on hidden once throttling allows it. |