desktop: Soft Tactile onboarding — indigo side rail and every wizard step

[plombeer31]

Part of the Soft Tactile desktop redesign. Depends on #440 (base branch facelift/1-foundation); every region PR can merge in any order after it. The integrated build is facelift/integration.

Soft Tactile, first-run wizard (ON-01…23). Builds on the foundation PR. The reducer, key router, stamps and copy constants are untouched.

What changes

• Title card: full indigo with a soft brand glow, 96px app mark, 64px "Atomic Agent", mono build line, "Click anywhere, or press any key".
• Indigo side rail on every later step: the app mark and name, a statement for the phase ("Choose how it runs. Change it any time." for setup; "Bring what you already taught other agents." for data), the 01 Setup / 02 Data steps with a tick when done, build line, soft orbs, room for the real traffic lights. At 940×620 it narrows to 272px and drops the statement.
• Right column: 34px title, lede, body, action bar (quiet left, primary right), keycap hint strip.
• Route choice: three cards with icons and 1–3 keycaps; the selected one has a brand ring; a Continue button presses Enter.
• Local models: a lifted list with real model logos; Best fit (indigo), Recommended / New (blue), Use at your own risk (amber); green or amber fit lines; the out-of-reach block as a quiet, non-clickable well; the Hugging Face row with its mark.
• Hugging Face: a pill field with the mark and Clear inside it, the error as a notice; the file pick as radio rows with the projector line and RAM warning as notices.
• Download: real progress bars and the two offers as cards with their keycap; the failed state keeps its fallback wording.
• Cloud: provider and model logos, green Configured, search as a pill with esc; the key screen with the provider mark; could not reach in amber with Save unchecked / Try again, a rejected key in red.
• Custom endpoint and embeddings: pill fields with error notices.
• Import: tick boxes with source marks (the app mark for the terminal agent), the scanning notice, the summary as a card, failures as a table, "Start using the agent" in brand blue.

Found while integrating

• A load-sensitive miss that 0.5.5 has too. With four keyed onboarding-mouse.mjs runs driven at once on one Mac, the wizard sometimes misses a click on the import or download-offer steps because the step it expects has already moved on. In the final batch, two runs on a0811bc3 and two on this work ran side by side and all four failed at the same step (no clickable element containing "Claude Code"). Earlier batches passed or failed depending on machine load, on both builds. JS render cost, animations, idle rebuilds, scroll containers and hit-test rules all measured the same as 0.5.5.
• The orbs' blur filter is gone. filter: blur(2px) on the rail's two decorative orbs drew nothing visible (their gradients already fade out) and only added a paint surface, so it was removed. That is not claimed as the fix for the miss above.
• A single, unloaded keyed run passes 61/61.

Verified

• onboarding-mouse.mjs 60/60 (the whole wizard with the mouse, plus the resting-state review).
• model-picks.drive.mjs: every wizard check passes at 68, 8 and 4 GB; its red checks are all in Settings › LLM › Local (the Settings LLM PR).
• Trusted walk: splash → keys → local list → bogus Hugging Face id → cloud list → / search → key screen → a rejected custom key → http://127.0.0.1:8080 error → embeddings; the local list under --fake-ram=8.