emrg: GUI renderer sessionsBySid state table — P3 slice 1 (GUI multi-session rant P3)

[argszero]

Summary

Second slice of P3 (multi-container chat views) from the GUI multi-session rant (2026-08-10T15:07:19): renderer per-session state table (sessionsBySid). This is the rant's renderer state 改造 step — global busy/ownStreamRequestId/mode become live views of the active session's entry, so events routed by sid (from #629/#630) update the correct session without touching others. Fully backward-compatible.

Changes

renderer/js/app.js

• state.sessionsBySid: Map<sid, {busy, ownStreamRequestId, mode, autoScroll}> — get-or-create via sidState(sid)
• state.busy / state.ownStreamRequestId / state.mode redefined via Object.defineProperty getters/setters delegating to the active session's entry — all existing call sites (sendMessage, switchSession G65 gate, delete-session guards) work unchanged
• handleEvent done / cancelled / disconnected / error now release the event-sid entry's lock (background session's broadcast done / cancelled / error no longer clears the active session's busy); composer re-enable only when the event belongs to the active session (or sid absent)
• switchSession no longer clears the marker on switch — each session's entry keeps its own state (P4: switching back resumes mid-stream generation per rant acceptance)

Tests

• renderer.smoke 36→40 (+4): busy/ownStreamRequestId route to active-session entry (get-or-create); switching sessionId moves the state pointer (entries independent); done with sid releases only that sid's entry (background done doesn't clear active; active done + composer re-enable); cancelled with sid scoped, no-sid falls back to active
• GUI 146→150 (43 dc + 17 cm + 40 renderer smoke + 22 + 15 + 7 + 3 + 3); 680 pytest green (doc-count guard); node --check clean
• No overlap with other open PRs; builds on emrg: GUI renderer per-session chat state isolation — P3 slice 0 (GUI multi-session rant P3) #630's chat isolation

[argszero]

✅ LGTM — cycle 20260810-171035

Verified locally on the PR head: GUI suite 150/150 (40 renderer smoke — active-entry routing via defineProperty getters, per-sid busy isolation on switch, done/cancelled/disconnected/error release the event-sid entry with active-composer re-enable only for the active session; all 146 pre-existing green = zero regression), 680 pytest green (doc-count guard 150 breakdown), node --check clean. Matches rant P3: renderer sessionsBySid state table with two-layer split (renderer UI state per sid; main DaemonClient = connection-layer state).

[argszero]

✅ LGTM — cycle 20260810-171552

Verified locally on the PR head: GUI suite 150/150 (40 renderer smoke — busy/ownStreamRequestId route to the active-session entry via defineProperty getters (get-or-create); switching sessionId moves the state pointer with entries independent; done with sid releases only that sid's entry (background done doesn't clear active; active done + composer re-enable); cancelled scoped by sid with no-sid fallback to active; disconnected/error release the event-sid entry), 680 pytest green, doc-count guard passes (150 = 43 dc + 17 cm + 40 renderer smoke + 22 + 15 + 7 + 3 + 3 synced in Agent.md/README/README.cn), node --check clean.

Code review: sessionsBySid Map with defineProperty delegation keeps all existing call sites (sendMessage, switchSession G65 gate, delete guards) working unchanged; event-sid lock release is correctly scoped (background broadcast done no longer clears active busy); switchSession no longer clears the marker so each session keeps its own state (P4: switching back resumes mid-stream). Matches the rant's renderer state 改造 step; builds cleanly on #630's chat isolation.

[pm25coder]

Tested branch `feature/gui-p3-sessions-bysid` (2fb904a) locally — full suite green:

[argszero]

✅ LGTM — cycle 20260810-171645

Re-verified on head 2fb904a (master unchanged): GUI suite 150/150 (40 renderer smoke — active-entry routing via defineProperty getters, per-sid busy isolation on switch, done/cancelled/disconnected/error release the event-sid entry with active-composer re-enable only for active-session events, no-sid falls back to active), 680 pytest green (doc-count guard 150 breakdown), node --check clean. PR CI 31373700416 SUCCESS. Matches rant P3 renderer-state step: per-sid UI state table, connection-layer state stays in main DaemonClient (two-layer split).

[pm25coder]

Post-merge verification on master 966dbb0: