Move terminal side-effect authority to a main facts channel

[nwparker]

Summary

Phase 3 slice 2 (design: docs/reference/terminal-side-effect-authority.md). Terminal side effects for PTYs whose bytes transit main (local-daemon + SSH) are now derived once in the main process and delivered to the renderer as facts, replacing renderer byte parsing for those PTYs.

• new batched pty:sideEffect channel: per-chunk facts (title / bell / agent-working / agent-idle / agent-exited) in byte order with attribution + output seq; bell detector lifted to src/shared/terminal-bell-detector.ts
• one renderer subscriber (terminal-side-effect-facts-handler.ts) with exactly-one-consumer-per-PTY semantics, title-only replay snapshots (no historical-bell attention), and a seq guard against snapshot/live races
• authority is structural per PTY kind: remote-runtime PTYs keep renderer parsing permanently; local/SSH flip behind settings.terminalMainSideEffectAuthority (default on, read synchronously pre-hydration so the kill switch holds at app-restart bindings)
• the parked byte watcher uses fact mode for covered PTYs (no double-fire); mounted panes register the same policy callbacks as fact consumers at all binding sites
• synthetic agent title/permission frames now ingest into main's tracker via a stateless frame parser (fresh detector instance — zero shared state with real chunk parsing); the legacy pty:data copy remains until slice 3

Review hardening (3-lens adversarial review, all findings fixed with tests)

• main's tracker is seeded from PTY records/daemon snapshots so app relaunch cannot lose parked working→idle completions or strand stale 'working' titles (red-verified)
• spinner ticks no longer fan out mobile session snapshots at ~12.5 Hz per pane (decorative gate on braille-stripped normalized title + status)
• per-chunk cross-channel order fixed to agent-status → side-effect facts per the design contract
• stale-title-derived idle clears titles/cache-timer but never schedules a completion OS notification (tag threaded through BOTH title and idle facts — the pane path classifies titles independently)
• hot-path scan merge, finally-flush seq integrity, headless-serve allocation skip, snapshot cursor-literal drop

Validation

• typecheck clean (including web-preload parity stubs); oxlint clean
• 1,032 unit tests across 23 suites green, including the byte-vs-channel store-outcome parity harness and bell-ordering parity cases
• e2e with the flip default-ON: terminal-attention, droid-notification, parking 3/3, parked-memory 2/2, hidden TUI restore 4/4, sleep/wake, golden 2/2 — all green (17-test sweep pre-fix, 14-test sweep post-fix)

Cut-off

Independently mergeable. Slice 3 removes the synthetic pty:data legacy copy and adds OSC 133;D + PR-link facts; slice 4 retires the watcher's byte sidecar.

Made with Orca 🐋

[ghost]

Ready to review this PR? Stage has broken it down into 9 individual chapters for you:

	Title
1	Define side-effect fact types and settings
2	Lift bell detector to shared utilities
3	Enhance title tracker for main-process authority
4	Implement side-effect tracking in main runtime
5	Expose side-effect channel via IPC and Preload
6	Extract notification policy and implement fact consumer
7	Wire fact consumer to terminal panes
8	Wire fact consumer to parked tab watcher
9	Update documentation for side-effect authority

_{Chapters generated by Stage for commit 3bd15ec on Jun 17, 2026 9:34am UTC.}

[nwparker]

Closing as superseded by merged PR #7214 (merge e84a8dd), which explicitly revived the complete term-speed-2 model/view chain into current main and then added newer scheduler, producer flow-control, snapshot, and reliability work. This old component/rollup branch no longer has an independent delta to rebase.