M7: Show a working scanner while a Turn works

[Sandstorm831]

Parent

Spec #276; implementation sub-issue of M7 #275.

What to build

While the Run Projection reports a live Turn, the Workbench shows OpenCode's block scanner beside plain words saying the agent is working and naming the interrupt key. The scanner is rebuilt, not copied: 8 cells, 40 ms frames, a trail in the accent colour, ■ for active and ⬝ for inactive cells, drawn from existing OpenTUI primitives with its provenance recorded. With animation off it becomes a static [⋯]. It stops when the Turn ends (stories 93–95).

Acceptance criteria

• Renderer tests prove the scanner shows during a live Turn, stops when it ends, and becomes the static marker with animation off, with the working words present in every case.
• Meaning never depends on motion or colour.
• The scanner's vendor provenance record passes the structural step.
• Prototype Crucible's launch and Run information architecture #23 evidence: keymap and focus, small terminals and resize, large content, interaction tuning, meaning without colour, and renderer and platform evidence, each shown by testRender frames with the fake Renderer Port.
• CI scenario: the Workbench renderer tests are green on Windows x64, macOS arm64, and Linux x64.

Blocked by

• M7: Report structural violations from one rule catalogue in a dedicated gate step #277
• M7: Report guidance-structure violations in the contract and check Module guidance shape #278
• M7: Report vendor-provenance violations in the contract #279
• M7: Report release-workflow violations in the contract #280
• M7: Enforce unused code and clear today's findings #281
• M7: Fail lint on any warning and add two OpenCode style rules #282
• M7: Label who holds the Turn and settle an interactive send on admission #290

Implementation packet

Owner: TUI presentation (Workbench working indicator), vendor provenance record

Ratchet: renderer tests for scanner on, off, and reduced motion

Deletes: nothing

Gate: ADR 0027 three-OS CI and recorded human evidence, with the slice scenario above.

Dependencies: no new runtime dependency

[Sandstorm831]

Starting context

Draft written against b976b6c while #290 is still open. Refresh it when #290 closes and this ticket is labelled ready-for-agent. OpenCode is cited at 228e9095ba, the snapshot the session-screen research used. UPSTREAM pins 1ead9e3d7f. Between the two commits ui/spinner.ts is identical, and component/prompt/index.tsx differs only in three ...→… strings (L1316, L1319, L1540), so the scanner lines match at both.

Input	Why it matters	Authority
Spec #276 stories 93–95, Implementation Decisions › Run Workbench › Working indicator, Cross-cutting › OpenCode, and Testing Decisions › Seams 4 ("scanner on and off")	The target: 8 cells, 40 ms frames, a trail in the accent colour, ■ active and ⬝ inactive, and a static [⋯] with animation off. It shows while the Projection reports a live Turn, beside words saying the agent is working and naming the interrupt key. It is rebuilt from OpenTUI primitives, with no new dependency. The spec does not say what turns animation off, or where the scanner sits for an Agent-step Turn, which has no interactive input.	Canonical spec
OpenCode 228e9095ba packages/tui/src/ui/spinner.ts:L272-L329 (createFrames), :L199-L244 (trail and inactive colours), :L25-L139 (scanner position and trail index); packages/tui/src/component/prompt/index.tsx:L1322-L1344 (spinnerDef), :L1513-L1527 (status row, interval={40}, [⋯] fallback), :L1587-L1592 (esc interrupt beside it); packages/tui/src/component/register-spinner.ts:L1-L6	What to rebuild against. createFrames defaults: width 8, holdStart 30, holdEnd 9, 6 trail steps, blocks style. That makes 8 + 9 + 7 + 30 = 54 frames, a 2.16 s cycle at 40 ms (computed from the constants, not timed). Up to 6 cells are ■ at once. OpenCode colours it with the agent colour, inactiveFactor: 0.6, and minAlpha: 0.3. The spec picks accent instead. animations_enabled is a key-value toggle in OpenCode's command palette. The <spinner> element comes from opentui-spinner 0.0.7. That package is not a Secant dependency. Read from its npm tarball, it is a Renderable that advances frames on an unref'd setInterval and draws each cell's colour itself.	Research
OpenCode session-screen research › working indicator and the busy-scanner row	The scanner shows whenever the session is not idle, and it looks the same for thinking and tool work. A permission prompt replaces the prompt and its status row, so no scanner shows while OpenCode waits on the human. Secant can derive "busy" above the Harness Seam.	Research
UPSTREAM header pin, rebuilt-against rules, the #219 prompt-study entry, checkVendorProvenance's record check, and change review › UPSTREAM currency	Vendor provenance record touched. The scanner is not vendored. It is a rebuilt-against entry in the #219 Taken/Changed form, and no file carries the Vendored from OpenCode marker. The structural step only checks that UPSTREAM exists once some file carries the marker. It never reads entries, so the "passes the structural step" criterion holds whatever the entry says, and only review keeps the entry honest.	Current guidance
InteractiveInput, with its live-Turn hint, and INTERACTIVE_HEIGHT	The input has three fixed rows: label, field, and a hint line that a refusal replaces. During a live human Turn the hint leads with esc esc interrupt so a narrow clip keeps the key. The scanner and its words must fit these rows, or the height and its accounting change together.	Current behavior
The Workbench's Turn-scoped Offers, rail accounting, interactiveTurnLive, the rail's interrupt and steer rows, and the bottom region; the Projection's liveTurn and Turn-scoped Offers	During an Agent-step Turn, the only live-Turn rows are the Actions rail's interrupt and steer rows. RunView has no live-Turn field, so interrupt-turn is present exactly when this process holds a live Turn. A Harness Request or free-text gate hides the rail and replaces the input (modalControl).	Current behavior
Measured at b976b6c with a scratch Port probe on 2026-09-30: an Agent step with a fake Claude Code Turn that blocks. See also the Turn-writes invariant.	The open run Projection got a durable running update with only cancel-run, then one live update at phase working. No durable update carried interrupt-turn until the Turn ended. A fresh read during the Turn offered interrupt-turn, steer-turn, and cancel-run. So in production, the Workbench does not see a live Agent Turn either. #290 measured the same gap for a human Turn.	Current behavior
tui notes: one string child per <text>, the Renderer Port rule, and clip in display columns; the Port is lifecycle only; accent	A per-cell trail cannot be literal and {expr} siblings in one <text>. Use one string per <text>, for example one <text> per cell in a row box. The Port carries no clock, and nothing here asks for one. ■, ⬝, and [⋯] measure 1, 1, and 3 columns with string-width 7.2.0 and with Bun.stringWidth (probed).	Current guidance
ADR 0036 › Colour and Bottom region and ADR 0037's deferral	ADR 0036 is the later redesign: the scanner under the prompt, only while a Turn works, beside esc interrupt. Do not contradict it. ADR 0037 defers "animation or mouse settings". Secant has no animation setting, environment variable, or stored preference (searched src/).	Advisory
Workbench renderer tests: liveTurnRunOf and its Offers, liveInteractiveRunOf, the live interactive Interrupt and its small-terminal check, the request modal owning Esc, noOverflow, and the fixture's bounded until	Fixtures touched, and the prior art for the on, off, and ended cases at small widths. Snapshots are hand-built, so these tests pass whatever the Projection pushes. They cannot catch the production gap above.	Current tests
Workbench › modal stack	Amend it if the scanner joins the interactive hint line or the rail row it describes.	Current guidance

Open for the human

Choices the spec leaves open, each with the drafting recommendation. They are settled with the human when this context is refreshed for ready-for-agent.

1. What turns animation off. ADR 0037 defers animation settings, and Secant has no switch. Recommend: build the static [⋯] branch behind a Workbench option that is private to the TUI, animated by default, and set by tests. Add no user switch in M7, and record the switch as ADR 0037's deferred setting. Why: the working words already carry the meaning (story 94), and an environment variable or stored preference would add a user-facing setting that neither the spec nor ADR 0037 grants. If users must be able to reach it in M7, the human names the switch.
2. Where the scanner sits. Recommend: in the interactive input, on the hint line under the field, as <scanner> <working words> · esc esc interrupt — …. For an Agent-step Turn, lead the rail's interrupt row the same way. No row is added and actionLines is unchanged. Both disappear while a Harness Request or gate owns the bottom region. Why: OpenCode puts it under the prompt beside esc interrupt, and its permission prompt replaces that row.
3. If M7: Label who holds the Turn and settle an interactive send on admission #290's push covers only the interactive send. Recommend: before M7: Label who holds the Turn and settle an interactive send on admission #290 closes, ask it to publish every Turn admission, Agent steps included. Why: the gap above is one mechanism. Otherwise this ticket's Owner grows to the Application, and the packet line changes.

Reading rule

Start with the spec's Working indicator bullet and OpenCode's createFrames and status row, then InteractiveInput and the rail rows.

• Rebuild it. Paste no OpenCode code, add no marker, and add no opentui-spinner. Follow createFrames' constants and invent no other timing. Stop the timer when the Turn ends or the view unmounts.
• Show it only while the live-Turn signal holds, and keep the working words in every case: animated, static, and at narrow widths. Colour and motion never carry the meaning alone.
• Write the UPSTREAM rebuilt-against entry in the M6: Expose live Interactive interrupt and preserve its Session #219 form. Keep the header Commit: at 1ead9e3d7f, and put the same Taken/Changed summary on this issue (ADR 0018).
• When the blockers land: M7: Label who holds the Turn and settle an interactive send on admission #290 replaces interactiveTurnLive, a missing send Offer, with a signal read from the Projection's live Turn. It also rewrites the input's label and hint precedence and drops "… sending…". Re-read InteractiveInput and reuse M7: Label who holds the Turn and settle an interactive send on admission #290's signal and words, not today's lines. Confirm that an open run Projection now gets the live Turn at admission, for Agent-step Turns too. At b976b6c it does not (measured above).
• M7: Steer from the interactive input during an Interactive agent Turn #294 follows this ticket in the same input. M7: Take launch inputs in wrapping multi-line boxes #287 adds an UPSTREAM entry, and M7: Open both catalogs on search with nothing selected and OpenCode focus moves #284 and M7: Wrap transcript and timeline lines instead of clipping them #288 may, which is a trivial merge. M7: Move ids off the everyday Workbench header #293 edits the header and details rows in run-workbench.tsx and run-workbench-views.tsx, not the input.

Owner: TUI presentation (Workbench working indicator), vendor provenance record
Ratchet: renderer tests for scanner on, off, and reduced motion
Deletes: nothing
Gate: ADR 0027 three-OS CI and recorded human evidence, with the slice scenario above.
Dependencies: no new runtime dependency