fix(tui): chevrons re-toggle even when section default is expanded

[OutThisLife]

Summary

Recovers manual click on the details accordion. After #14968 introduced SECTION_DEFAULTS (thinking + tools default to expanded), every panel render OR-ed the local toggle against the resolved visibility:

open: visible.thinking === 'expanded' || openThinking

That pinned open=true for any default-expanded section, so clicking the chevron flipped openThinking but the panel never collapsed. Default config = chevrons effectively decorative.

Fix

Local toggle is the sole source of truth at render time. The useState init still seeds from the resolved visibility (so first paint matches the configured default), and the existing useEffect still re-syncs when the user mutates visibility at runtime via /details.

Same OR-lock cleared inside SubagentAccordion (showChildren || openX → openX) — pre-existing but the same shape, so expand-all on the spawn tree no longer makes inner sections un-collapsible either.

Files

• ui-tui/src/components/thinking.tsx — drop OR-lock from 4 panels in ToolTrail + 1 inline thinking arrow + 4 inner sections in SubagentAccordion. Anchor comment near the useState block to call out the contract so this doesn't regress again.

Test plan

• npm test (ui-tui) — 271/271 passing, no test changes needed (the bug was in the consuming component, not the resolver in details.ts)
• tsc --noEmit -p tsconfig.json — clean for my edits (pre-existing dom.ts warning untouched, same as feat(tui): per-section visibility for the details accordion #14968)
• npm run lint — same 23 problems as main (none in my diff)
• Manual: fresh TUI → click ▾ on Thinking → collapses to ▸; click again → expands. Same for Tool calls / Spawn tree / Activity.
• Manual: /details thinking collapsed then /details thinking expanded still routes to the local toggle correctly (initial paint matches config, subsequent clicks toggle).

[github-actions]

⚠️ npm lockfile hash out of date

Checked against commit f5e2a77 (PR head at check time).

The hash = "sha256-..." line in these nix files no longer matches the committed package-lock.json:

• nix/web.nix:7 (.#web): sha256-TS/vrCHbdvXkPcAPxImKzAd2pdDCrKlgYZkXBMQ+TEg= → sha256-Qq6cZscavrIpI2hy9PCPpPVfhr/d69QfKdqttv5YJ3s= — lockfile: web/package-lock.json

Apply the fix

• Apply lockfile fix — tick to push a commit with the correct hashes to this PR branch
• Or run the Nix Lockfile Fix workflow manually (pass PR #15266)
• Or locally: nix run .#fix-lockfiles -- --apply and commit the diff