Contour CAM: inside cuts inside, tabs hold, Run Job is not the default button

[ecto]

Why

Getting the rana-60-cnc stator ready to cut on the Anolex 4030, I replayed the app's generated G-code against the outline it came from before letting it near the machine. That check — not the preview, and not the existing tests, which only asserted that moves came back — found that the job would have destroyed the part.

Kernel (vcad-kernel-cam)

• Inside contours cut on the wrong side. Contour2D::inside() was byte-identical to outside(); both offset by +tool radius. The stator's bore-and-slots pass ran 3.2 mm into every post and the ring. inside is now a field and the compensation is signed.
• Cutter that does not fit — an inward offset that falls into several pieces used to follow the first piece silently; it is now CamError::ContourSplit.
• Tabs held nothing. Honoured on the final pass only (0.5 mm stepdown cut a 1 mm tab to 0.5 mm), width measured along the tool-centre path (4 mm → 0.8 mm of metal), a tab at position 0 clipped at the loop seam, entered along a ramp, and one landed inside the stator's 4 mm lead notch. Now: every pass below the tab top steps over it with vertical lift/plunge, width means metal left, the seam is handled, even spacing starts half a pitch in, and each tab settles on the nearest stretch that runs straight.
• Always retract straight up after the last pass.

Tests check the side (both windings), the metal actually left under each tab on every pass, the seam case, tab placement on a notched outline, and the neck refusal. The side and placement tests were mutation-checked (fail on the old behaviour).

Native app

• A contour imported as a through cut follows the stock thickness until its depth is edited by hand (importing before entering the thickness left the job blocked at 10 mm).
• Run Job was the window's default button. Its shortcut was ⌥⌘Return; AppKit exposes any Return-keyed button as the default button, so an accessibility client pressing "return" pressed Run Job, and the confirmation that followed had "Start machining" as its Return default. Shortcut is now ⌥⌘J; run / home / move-to / set-zero / run-macro dialogs default to Cancel. Verified live on the Simulator.
• CNCOutlineTests: VCAD_STATOR_GCODE_OUT dumps the job so it can be checked outside the app.

Result

First real cut with the fixed CAM: the stator profile in a 1 mm copper plate, Ø2 2-flute, sent from ncSender — clean profile, cutter survived. docs/native-app-friction-log.md items 32–54 record everything hit along the way, fixed and open.

Testing

• cargo test -p vcad-kernel-cam (71 pass), cargo test -p vcad-ffi cam, cargo clippy -p vcad-kernel-cam -p vcad-ffi -- -D warnings, cargo fmt --check
• swift test --filter "CNC|DesignShellTests|WorkspaceSwitchTests" (35 run, 0 failures)
• Exported jobs verified against the outline: worst deviation 0.013–0.018 mm (polyline tolerance), no rapids below Z0.5 with XY motion

No generated WASM artifacts are touched.

🤖 Generated with Claude Code

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Project	Deployment	Actions	Updated
vcad-mcp	Building	Preview	Sep 17, 2026 7:39pm UTC

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vcad	Ignored		Sep 17, 2026 7:39pm UTC
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