Add ASCII wireframes of UI changes, independent of the Playwright preview

[graycyrus]

Summary

• New src/wireframe module: one model call over a pull request's UI-touching diff files, asking for a compact before/after ASCII wireframe of each screen or modal the diff adds, removes, or changes.
• Deliberately independent of src/preview end to end — no browser, no target-repo CI, no dependency on whether a repository has opted into actions/ui-preview. is_ui_path is duplicated rather than imported from preview::plan so the two heuristics can't drift into each other by accident.
• Published as its own durable comment (src/app/apply.rs::publish_wireframe, marker wireframe::render::MARKER), edited in place on every push — not folded into the review hub, since a screen-by-screen gallery can be the bulkiest thing the bot posts.
• Wired into Proposal::wireframe in src/app/review.rs, the same shape Proposal::overview already uses.
• [wireframe] config: on by default; enabled/max_screens are repository-overridable (only downward, same posture as preview.enabled/max_flows); max_width/max_height stay operator-only, same reasoning as [grouping]'s ceilings.

Test plan

• cargo fmt --all -- --check
• cargo clippy --locked --all-targets -- -D warnings
• cargo test --locked (2036 passed)
• cargo check --locked --all-features --all-targets
• Golden tests for the model call (added/removed screens keep only the relevant side, a wireframe past the width/height ceiling is clamped, screens past max_screens are dropped and counted) and for the rendered comment body

[tinysweeper]

Tiny Sweeper review

⚠️ Review failed for 1abe931f2c47. the review of #190 did not finish within 900s

[coderabbitai]

Important

• 🔍 Trigger review

This repository does not receive automatic reviews because it has fewer than 10 stars.

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Advanced

Run ID: 82c19400-8370-4f42-8c0a-3ec0c50a8816

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