feat(meetings): capture system audio in Electron

[kaizawa97]

Stacked on #5738 (pr/meetings-recording-core) and unmergeable before it: systemAudio.ts / the capture pipeline this extends land there. Until #5738 merges (or is rebased), this PR's diff shows both commits and it will report conflicts with main exactly as #5738 does; only the feat(meetings): capture system audio in Electron commit is for review here. I will rebase this branch as soon as #5738 lands.

Problem / Motivation

In a browser tab, system audio (the remote side of a Zoom/Chime call) is only reachable through a display-capture prompt, and on some platforms not at all. So in the desktop app — the place most likely to be running next to a call — a meeting records only what the microphone picks up.

What changed

• Electron's display-media handler resolves a loopback audio track directly, no picker prompt: website/electron/display-media.js grants the request with system audio where the platform can provide it, and preload.js exposes the capability to the renderer behind the existing bridge.
• The capture tier is probed, not assumed (audio/captureTier.ts): the frontend inspects the track it actually received and reports which tier it got. A platform that cannot provide system audio degrades to microphone-only instead of recording silence — the failure a hardcoded assumption would produce.
• One catalog key added to all 13 locales; spec updated in the same commit.

Tests

• website/src/test/MeetingsCaptureTier.test.ts (16 tests) — the tier probe and each degradation path.
• website/electron/test/display-media.test.js (17 node:test cases) — the main-process handler's grant/refuse branches.

Both suites run green on the branch (Linux, node 22). tsc -b does not pass on this branch's checkout because the stack's base predates the main-branch repair in #5522 (useDialogFocusTrap.ts) — untouched by this change and resolved by the rebase onto #5738's post-rebase head.

Manual verification

Not yet performed on a real desktop build; loopback capture availability differs per OS and needs a hands-on pass (macOS in particular) before merge sign-off.

Related Issues

Part of the meetings feature stack split from the feat/meetnote branch; depends on #5738, independent of #5741/#2190/#7194.

no linked issue: feature work from the meetings stack; no tracked issue exists for it.

[bolichen97]

Audit note — this PR and #5738 are one branch stack, not duplicates

A duplicate-detection sweep flagged these two as near-identical because they share a large block of added lines. They are not duplicates: one branch contains the other's commits, so the shared lines are inherited, and the review diff overstates what this PR actually authored.

This is the textbook stacked-branch artifact, provable by SHA rather than by reading code: git rev-parse pr/5738 = 4bb2f16 and git rev-parse pr/7196^ is the SAME sha, off the same merge base abc8222. git log <mb>..pr/7196 is exactly two commits (4bb2f16 then 375f708) while git log <mb>..pr/5738 is exactly one (4bb2f16). So #5738's entire 41-file/+5212 diff appears verbatim inside #7196's three-dot diff, and the 41 shared files are a STRICT SUBSET of #7196's 47 (comm -23 on the two files.tsv is empty). Only #7196's own commit -- 22 files, +597/-15, none of them backend -- is its own work, and it is strictly additive: it never rewrites a line #5738 wrote, it extends #5738's systemAudio.ts, SYSTEM_AUDIO_KEY and meetings.md Recording section on top. Neither PR duplicates the other's behaviour: #5738 is the backend recording subsystem plus browser capture, #7196 is the Electron main-process loopback grant, and #5738 touches no file under website/electron/ at all.

What is genuinely each PR's own

If #5738 merges, #7196 still carries all of its own work and loses nothing: 6 files #5738 never touches (website/electron/display-media.js +102, main.js +35, preload.js +27, electron/test/display-media.test.js +95, website/src/apps/meetings/audio/captureTier.ts +95, website/src/test/MeetingsCaptureTier.test.ts +171), plus its 35-line extension of systemAudio.ts, the 3-line no-loopback row in SYSTEM_AUDIO_KEY, one catalog key in 13 locales and 36 lines of spec. That is the whole capability of granting real system audio in the desktop shell and degrading to mic-only where the platform cannot -- unlanded and unduplicated. The dependency runs one way only: #7196's own commit CANNOT apply to main alone, because website/src/apps/meetings/audio/ does not exist on origin/main (git ls-tree empty) and SYSTEM_AUDIO_KEY/sysAudioUnsupported have zero hits there, so the files it modifies are created by #5738. Correct sequencing is #5738 first, then #7196 rebases; #7196 merging as-is would simply carry #5738's commit in with it, which is not redundancy but the base of the stack.

Suggested action

Land #5738 first, then rebase #7196 onto main so its diff shrinks to its own work. Reviewing #7196 before that means reviewing #5738's code twice.

---

_{From a repository-wide duplicate/overlap audit of every pull request open against main (2026-09-02, 330 PRs, one reviewer per PR). Each PR was read as its full merge-base diff plus its description and every comment and review, then compared against each candidate PR's own diff and against origin/main at 1a765b88ceb7. This PR is not being closed — the note is informational. If the reading is wrong, please correct the reasoning rather than just the conclusion.}

[bolichen97]

Open PR relationship audit

This is a consolidated, point-in-time code-level audit note. It compares complete merge-base diffs and current/merged code; it does not treat a shared topic as duplication or partial coverage as completion.

Relationship findings

• PR #5738 is OVERLAPPING relative to this PR. The goals differ or the implementations can complement each other; this is not a duplicate claim. Recommended action for PR #5738: CONTINUE_DEVELOPMENT. A branch stack, not a duplicate: PR #5738 is the base and PR #7196 is the dependent. Land PR #5738 first and have PR #7196 rebase onto it. Closing PR #5738 in favour of PR #7196 would be closing the base in favour of the tip and would silently make the whole 5212-line backend subsystem land under the wrong review. Files: src/kiro_crew/recording/ws.py, website/src/apps/meetings/audio/systemAudio.ts, website/src/apps/meetings/hooks/useMeetingSession.ts.
• PR #5741 is OVERLAPPING relative to this PR. The goals differ or the implementations can complement each other; this is not a duplicate claim. Recommended action for PR #5741: KEEP. Materially different scope (live system-audio capture in the desktop shell); no shared behavior with the import route. Files: src/kiro_crew/recording/ws.py. The two independent directions used different labels; the matrix conservatively retains OVERLAPPING for coordination.
• This PR is OVERLAPPING with PR #7194. The goals differ or the implementations can complement each other; this is not a duplicate claim. Recommended action for PR #7196: REBASE. Complementary meetings features sharing the manifest, app.json permission list, MeetingView header and useMeetingSession surface. Whichever lands second resolves the highlight renumbering; no code needs to be dropped. Files: website/src/components/appstore/appManifest.ts, src/kiro_crew/apps/builtins/meetings/app.json, website/src/apps/meetings/MeetingView.tsx.
• This PR is OVERLAPPING with PR #7532. The goals differ or the implementations can complement each other; this is not a duplicate claim. Recommended action for PR #7196: REBASE. A merged refactor moved this PR's host code out of main.js into window-lifecycle.js, so the change must be re-applied there and its source-pinning test updated. Independent of the PR #5738 stack. Files: website/electron/main.js.

No PR, Issue, label, branch, or review state was changed by the relationship-note portion of this audit.

[NicholasRBowers]

🤖 Kiro Crew [operator: NicholasRBowers#a942f9ca]: This PR has been inactive for 7+ days. I reviewed the blockers but they require your input:

• The PR is stacked on unmerged feat(recording): capture meeting audio over a WebSocket #5738 (itself conflicting with main); only you can sequence the rebase once the base lands.
• A merged refactor moved this PR's website/electron/main.js host code into window-lifecycle.js — the change needs re-applying there and its source-pinning test updated (per the 2026-09-04 audit note).
• Your body flags the outstanding hands-on pass: loopback system-audio capture differs per OS and needs real macOS/Windows verification before merge sign-off — a Linux automation host cannot provide that.
• Coordination: feat(meetings): add a per-meeting note the user owns #7194 overlaps on manifest/app.json/MeetingView — whichever lands second rebases.

When you've addressed these, the pipeline will re-assess on its next cycle.

[bolichen97]

Attempted a rebase onto main 8534cbf7 as part of the 2026-09-08 open-PR audit. Aborted, branch untouched — the conflicts need your decisions, not a mechanical resolution.

They land in the parent commit (4bb2f165d, i.e. #5738), 21 files:

• website/public/pcm-worklet.js — main replaced the decimator with a polyphase anti-aliased resampler; where the two-input sum belongs relative to the new filter history is your call.
• website/src/apps/meetings/MeetingView.tsx — main moved the action bar into an overflow menu (it says five sibling buttons breached the two-per-row cap) and added translation; the recording/system-audio controls need placing in that new shape.
• src/kiro_crew/config/loader.py — now a facade over config/sections.py; RecordingConfig needs a home there.
• security_posture.py, config-baseline.json, useMeetingSession.ts, useMeetingTranscription.ts, meetings.md, 13 locale catalogs.

Also pending on this PR's own commit: merged #7532 moved setDisplayMediaRequestHandler and additionalArguments out of website/electron/main.js into window-lifecycle.js, so that hunk no longer applies and MeetingsCaptureTier.test.ts's three source-pinning assertions must be repointed.

Suggested order: land #5738 first, then rebase this branch so its diff is just its own 22 files.