Harness Inspector workbench declutter

Traceability

• Spec ID: harness-inspector-ui-declutter
• Status: Draft

Intent

The Date view of the Harness Inspector report renders one workbench card per session, and a screenshot review against real workspace evidence showed most of the rendered area is redundant: every card repeats the same "Activity on <date>" title, empty lanes are stretched to a fixed 320px height, per-card lane resizers behave independently, mid-width viewports clip the third lane, and the prompt-lane counter prints three numbers that are almost always equal. This spec removes that redundancy so a reader can scan a day of sessions without scrolling through empty panels or clipped content, while keeping the existing report model, privacy boundaries, and picker behavior unchanged.

Acceptance Scenarios

• AC-1: A lane whose only content is an empty state (no retained prompts, no session link, zero normalized calls, or no linked commits) renders as a compact single-line hint instead of a 320px-tall dashed panel, and a card whose lanes are all empty stays visually short. A session with zero normalized calls does not render an "Expand 0 normalized actions" control.
• AC-2: In Date scope, a card with a linked session uses a session-derived title (first retained prompt text, falling back to the session locator) instead of repeating "Activity on <date>", and the card kicker no longer repeats "Date scope" on every card. The commits-only row keeps a descriptive title. Feature/story scope titles are unchanged.
• AC-3: The workspace scroll container allows horizontal scrolling at any viewport width, and the workbench grid minimum width matches the sum of its lane minimums, so no lane or card edge is clipped at desktop widths.
• AC-4: Dragging or keyboard-adjusting any lane resizer updates a shared lane width applied to all workbench cards in the list, and the shared width survives re-rendering the scope.
• AC-5: When retained, normalized, and observed prompt counts are equal the prompt lane shows a single "N user turns" count; the three-part breakdown only appears when the counts differ.
• AC-6: Feature Tree rows suppress the evidence badge for the default declared evidence; non-default evidence such as candidate keeps its visible badge so the picker-footer distinctness promise still holds.

Non-goals

• No changes to report-model.mjs, feature-tree.mjs, cli.mjs, or the privacy/redaction pipeline.
• No changes to the Feature Tree picker semantics beyond hiding the default declared badge (AC-6); checkboxes, node counts, and non-default evidence badges are unchanged, as is the session detail view.
• No visual redesign beyond removing the redundancy listed above.

Plan and Tasks

All changes live in scripts/harness-inspector/ui/:

1. workbench.js
   • promptLane / activityLane / deliveryLane: mark empty lanes with a lane-empty class; skip the activity-details disclosure when totalCalls is 0; skip the delivery Hide/Show toggle when no commit is linked (AC-1).
   • workbench: for date-scope items derive the title from the first retained prompt or the session locator, and replace the repeated "Date scope" kicker with a session/commits kicker (AC-2).
   • Resizer pointer and keyboard handlers: write --prompt-width / --delivery-width onto the persistent #workbench-list element instead of the per-card .workbench element (AC-4).
   • promptLane counts: collapse equal shown/normalized/observation counts into one "N user turns" label (AC-5).
2. workbench.css
   • Drop the fixed .lane min-height:320px; style .lane-empty and its .empty-state as a compact hint row (AC-1).
   • Reduce .workbench-grid min-width to the lane minimum sum (730px) and make .workspace-scroll \{ overflow-x:auto \} unconditional (AC-3).
   • Clamp .workbench-head h3 to two lines so prompt-derived titles cannot blow up the card header (AC-2).
3. render-html.mjs featurePicker: emit the tree-row evidence badge only when the node evidence differs from the default declared (AC-6).
4. test/harness-inspector.test.mjs: extend the existing HTML rendering assertions to cover the new markup (lane-empty markers, session-derived date titles, shared-width resize script, merged turn count, suppressed declared badge).

Test and Review Evidence

• node --test test/harness-inspector.test.mjs — AC-1..AC-6 markup and script assertions plus existing AC-2/AC-3/AC-5/AC-6/AC-7 regressions.
• Manual: node scripts/harness-inspector/cli.mjs render --out .qoder/inspector-preview.html, serve locally, screenshot Date view at ~880px viewport and verify no clipped lane, no repeated "Activity on" titles, compact empty lanes, and synchronized resizers.
• Risk: the report HTML is self-contained and read-only; the change is contained to UI assets, so the main risk is breaking existing HTML assertions, covered by the test suite.