fix: point shapes are now selectable and deletable by clicking

[wkentaro]

Problem

Point shapes placed on the canvas cannot be selected or deleted by clicking on them. Shape.containsPoint() calls self.makePath().contains(point), but a point shape's path is zero-area (a single zero-length line), so QPainterPath.contains() always returns False.

This makes point annotations effectively stuck — impossible to select, move, or delete after creation.

Fixes #1524.

Solution

Add an early return in containsPoint() for shape_type == "point" that uses the actual rendered hit radius (point_size / 2) instead of path containment:

if self.shape_type == "point":
    if not self.points:
        return False
    return labelme.utils.distance(point - self.points[0]) <= self.point_size / 2

This mirrors the visual size of the drawn point handle and gives users a natural click target.

Tests

Added tests/unit/shape_contains_point_test.py with 4 cases:

• Clicking exactly on the center → True
• Clicking within point_size / 2 → True
• Clicking more than point_size / 2 away → False
• Empty points list → False (no crash)

All 40 unit tests pass.