Clarify thread-search controls and result hierarchy

[brsbl]

Rebased head ab9a7f30e has passing remote CI. Fresh screenshots below compare current origin/main (4ed274321) with this exact head and include the exact parent/merge-base baseline. Nothing merged.

What was wrong

Prominent shortcut keycaps competed with results. Draft/Archived metadata could move neighboring content, and visible guidance lacked a direct accessible relationship to the search input.

What changed

• Keep Draft and Archived as quiet, non-shrinking labels at the right edge, preserving stable title/project/timestamp alignment and text-only result rows.
• Keep the footer persistent but contextual: Escape Close in commands; Command-Enter Split and Escape Back in thread search.
• Associate concise keyboard guidance with each input and hide decorative footer copy from assistive technology.
• Keep Threads on the shared active-tab fill and use tertiary shortcut chrome. Existing keyboard and navigation behavior is unchanged.
• Add focused lifecycle-placement, metadata-stability, filtering, footer/accessibility, tab-fill, and tertiary-keycap coverage.

Includes the parent's fixes for scope-menu clipping and archived threads staying readable in splits without unarchiving. No public or wire contracts changed. Page/plugin search expansion and lower-priority abstraction cleanup remain separate follow-ups.

Screenshots

Captured 2026-09-09 in the isolated branch web app, Chrome for Testing 153.0.8010.36, light theme, 1440×900 at DPR 1. Same dev database, synthetic archived reference, installed plugins, and /settings/keyboard route throughout.

• Thread search: Command-K, query “Archived design reference”, first result selected.
• Commands: Command-Shift-P, unfiltered command list at the top. Main's “>” prefix and the branch's empty query are their native shortcut behavior.
• origin/main advanced to 4ed274321 after the rebase onto 0b4115aa9; current-main comparison is intentionally separate from the exact layer baseline.

Current origin/main versus this PR

State	Before — current main 4ed274321	After — exact PR head ab9a7f30e
Thread search
Commands

Exact layer baseline — 68c157fdf

These are the matching before images from the parent PR head. The exact-head images above are the after images for this layer.

Thread search — before	Commands — before

Historical evidence from before the rebase

The following captures retain their original source revisions. They document earlier implementation and bug verification, not the current PR head.

Exact branch web app, same synthetic threads, active-thread route, query “Archived design reference”, light theme, and 1440×900 viewport in Chrome for Testing 153.0.8010.36.

Before — exact parent head aabc9dd13

After — reviewed pre-rebase head 56951e305

Integrated outcome — archived reference stays readable in a split

How you verified

• Fresh exact-revision visual evidence captured and inspected for thread search and the root command list, including opening, settled rendering, and Escape between modes. This was a bounded evidence refresh, not a repeated full QA pass. No product code changed.
• Pre-rebase remote CI passed checks, app/server/package/integration tests, contributor/version checks, and Linux/macOS package smoke. Workflow-configured iOS/Node Compatibility skips only. No local tests, typechecks, or lint.
• Chrome for Testing 153.0.8010.36 at 1440×900: Command-K search → Command-Enter archived split; readable archived content and unchanged archivedAt; hard reload retains panes/focus; archiving the active neighbor closes only that pane. Source CLI thread open … --split right also succeeds through the existing SDK-backed path.
• Prior bounded palette pass covered one-result scope selection without dismissal, input focus, Escape back/close, hard reload, and command navigation to Keyboard settings. Fresh pre-rebase screenshots above.
• No console errors, uncaught exceptions, or failed network requests during the archived-split product pass after synthetic timeline setup was complete. Earlier fixture-only 500s were corrected before the pass.
• Cumulative review completed; both P1 fixes resolved in their originating layers. No second review. The pre-rebase head was CLEAN and MERGEABLE. Nothing merged.

BB-Thread-ID: thr_ccffp4w2p2

AGENT GENERATED

[brsbl]

Superseded by #3370, which now contains the complete final UI diff directly on the functionality foundation. The final source head remains 75de5eb; this consolidation changes no product code. Discussion, commits, and the branch are preserved here. Nothing was merged.