# Wire & Line Removal Feature

## Description
Remove power lines and wires using contour detection with line brush fallback.

## Acceptance Criteria
- [ ] User taps near wire with Wire tool selected
- [ ] `VNDetectContoursRequest` returns all detected contours
- [ ] ContourService scores contours and selects best wire-like match:
  - Proximity to tap point
  - Thin/elongated aspect ratio
  - Straightness (low curvature)
  - Length
- [ ] Best contour highlighted for preview
- [ ] Mask width configurable: default 6px, range 2-20px via slider
- [ ] User confirms, mask expanded to configured width, inpaint executes
- [ ] Line brush fallback when no contour detected:
  - User switches to "Line brush" mode
  - User draws along wire
  - Consistent stroke width maintained
  - Stroke becomes mask for inpainting
- [ ] Multiple wires can be removed sequentially
- [ ] Performance: contour detection < 300ms

## Technical Notes
- Power lines against sky have strong edges - ideal case
- Scoring weights: proximity 0.3, aspect 0.3, straightness 0.2, length 0.2
- Line brush should use touch velocity for smooth strokes
- Consider Catmull-Rom spline for smooth line brush paths

## Edge Cases
- No wire-like contours found: "No lines detected. Use line brush" prompt
- Wire against busy background (buildings, trees): likely needs line brush
- Curved wires (drooping power lines): scoring allows moderate curvature
- Wire crosses entire image: may need to process in segments
- Multiple parallel wires: each tap selects one, remove sequentially
