UX pass: Variant B — cockpit-bar workbench

[halaprix]

Implements the approved SlotScope Workbench B.dc.html mock per the implementation prompt: the full measure loop (compile → deploy → call → step the trace → read named accesses) works on one screen at ≥75rem, and the storage picture never leaves the screen while stepping.

What changed

• 56dvh three-pane face (was 66dvh): Source · Assembly · Probe pane (Storage | Trace segmented modes, role="tablist"). Trace mode auto-enters when a call completes; a revert auto-selects the Forensics tab; manual flip back any time.
• Live storage strip pinned above the trace tabs at every cursor position: one mini 32-byte band per touched slot (byte 31→0), owner-hued static cells with full title/aria-label, hatched padding, keccak-derived slots as labeled derived bands. Bytes written up to the cursor fill amber with a caption naming slot · [hi:lo] · resolved label · new value · step. Amber narrows to the proven changed byte range (old→new diff); a first-touch write honestly claims the whole word.
• Cockpit bar: full-width, fixed-height — six steppers, scrubber, cursor facts, outcome line (gas · steps · returns). Cursor keeps driving the assembly-row + source-range highlights.
• Execute strip: address chip (Vault @ 0x… · local · cancun), Deploy locally/Redeploy, Abort, compact per-function forms; unsupported types disabled with the honest reason inline.
• Source pane docks the Contracts picker and a DIAG · n toggle in its header; the diagnostics strip expands inside the pane, auto-opens on error-severity diagnostics, shows byte ranges and "(whole file)".
• Lower grid is now Share (URL field permanently rendered at fixed height — the layout-shift pain point is gone) + Challenges. Narrow screens stack in the same order.
• Mechanics: ExecutePane's logic moved verbatim into useExecutionSession(); ExecuteStrip, CockpitBar (reusing TraceScrubber), ProbePane, LiveStorageStrip, ForensicsView are thin composition over the existing tested components. ExecutePane.tsx and TracePane.tsx deleted.

Honesty notes

• All EXACT/INFERRED/UNRESOLVED wording, raw fallbacks, "not tracked"/"not supported" notes, the keccak "not expanded" note, and the as-compiled environment echo survive verbatim.
• Amber appears only on measured facts (bytes proven written); resolution stays border-treatment + mark, never hue; owner hue stays identity with text chips.

Selector / test changes (as required by the prompt)

Change	Where
Region Contracts removed → assert the Contract combobox (same accessible name, now in the source pane header)	compile.spec.ts, lifecycle.spec.ts
Region Diagnostics is toggle-gated → specs open DIAG · 0 first when no errors (errors auto-open it, so error-path specs unchanged)	compile.spec.ts, lifecycle.spec.ts
Probe pane section is landmark Probe; the inner static grid keeps landmark Storage	axe landmark-unique fix; no spec change needed
Machine state lives behind the State tab → specs click it first	trace.spec.ts (X5, replay-consistency)
Events live behind the Events · n tab → specs click it first	events.spec.ts, a11y-v1.spec.ts
Runtime storage group lives in the probe pane's Storage mode → spec flips mode	semantics.spec.ts (S5)
execution-outcome moved to the cockpit bar (same testid, same text facts)	none needed
Deploy button reads Redeploy after first deploy (Deploy locally on fresh state — specs unchanged)	none needed
Benchmark harness asserts DIAG · 0 instead of the always-open diagnostics region	scripts/benchmark-report.ts

New testids: cockpit-bar, live-storage-strip. Unchanged and load-bearing: trace-pane, trace-cursor-facts, trace-stack/memory/io, trace-observations, events-panel, revert-forensics, jump-to-revert, deployed-address, share-url, share-size, migration-badge, byte-diff, keccak-flow*, storage-record, all stepper/scrubber aria-labels.

Verification

• 209 unit + 57 e2e green (axe both motion modes, reduced-motion equivalence, 200% zoom with only the grid scrolling internally, forced-colors, keyboard parity)
• Token discipline gate clean (no raw color literals outside tokens.css)
• Benchmark PASS (p95 action-to-paint 200.7 ms / 2000 ms budget)
• Out-of-scope surfaces untouched: compile spine, session codec, challenge content, tour, palette

🤖 Generated with Claude Code

[halaprix]

Review fixes landed in 83abd62: resolution pills moved off owner-b onto a dedicated neutral res tier (border style + mark carry status), COLD chips off pin cyan onto the label tier, and the probe header's CALL # now counts every executed call since deploy. 57 e2e green, token gate clean.