Clockwise-positive fine rotation + Straighten reference-line tool

[linkmodo]

Summary

Two alignment-workflow improvements that share one sign convention, plus a small dialog polish.

Clockwise-positive fine rotation

The Fine Rotation slider now reads in the photographer's convention: positive turns the image clockwise on screen, negative counter-clockwise — under every flip state. The crop tool's rotation-handle angle badge and the Alt+R / Alt+Shift+R shortcut descriptions follow the same convention.

The sign flips at the display boundary only; geometry.fine_rotation keeps its internal cv2/warp convention, so every previously saved edit renders exactly as before (negating the stored convention would have silently mirrored the tilt of existing edits, with no clean migration path). Because the pipeline applies flips before fine rotation, the stored angle's on-screen direction is flip-independent — verified empirically by rotating marker pixels with and without pre-applied flips — so the single display negation holds in all flip/rotation states.

Straighten reference-line tool

A ruler button under Geometry → Alignment (default key L, rebindable in Customize, listed in the Keyboard Shortcuts dialog under Geometry): activate, draw a line along a tilted horizon or a leaning vertical edge, and the image rotates to match on release — one-shot, like Lightroom's straighten line.

• Intent detection: lines closer to horizontal level to the horizon; lines closer to vertical plumb (e.g. a building edge). Drawing the same line from either end gives the identical correction.
• A live badge previews the correction while dragging: "Level +1.43°" / "Plumb −5.71°", in the CW-positive display convention.
• The delta is measured in display space and added to the current fine rotation (clamped to ±45°), landing in the same field the slider and crop handles drive — so it composes correctly under flips and 90° turns, and remains adjustable afterwards.
• Guards: sub-8px drags ignored (accidental clicks), right-click never draws, Esc cancels an in-progress line; screen-space measurement makes zoom/pan/HQ irrelevant to accuracy.

Dialog polish

The Keyboard Shortcuts dialog's Customize/Close buttons set widget-level stylesheets with hardcoded backgrounds, which beat the app stylesheet in every state and killed the global hover-grey / pressed-red feedback. Customize now inherits the standard button states; Close uses the app's primary treatment (accent fill with its own hover/pressed shades).

Testing

Verified in-app on Windows: slider direction under H/V flips and 90° rotations, straighten on horizons and verticals (both lean directions), badge signs matching the slider, L toggle + rebinding, saved edits unchanged. Unit tests cover the straighten math (axis snapping, both lean directions, direction-agnosticism, exact-axis no-op, ±45° bound) and a headless end-to-end drives press/drag/release through the overlay asserting emitted deltas. 103 geometry + shortcut-registry tests pass; ruff clean.

[marcinz606]

that straighten-to-line is great!