iter-png-1/claude-opus-4-5 / tier-2-l-bracket

画像を確認すると、以下の問題があります：

1. 内側コーナーが原点になっていない（水平面が-Z方向、垂直面が-Y方向に配置されている）
2. 穴の位置が「左右対称に2個」ではなく、中心線上に1列になっている（X方向に2個並ぶべき）

修正したコードを出力します：

```openscad
// L-bracket with countersunk holes

// Parameters
flange_width = 50;      // X direction
flange_depth = 40;      // Y direction for horizontal, Z direction for vertical
thickness = 3;

// Countersunk hole parameters
hole_diameter = 4.5;    // M4 through hole
countersink_diameter = 8;
countersink_depth = 2;
edge_distance = 10;     // Distance from edge to hole center

// Module for countersunk hole (pointing in +Z direction, countersink on top)
module countersunk_hole() {
    union() {
        // Through hole
        cylinder(h = thickness + 1, d = hole_diameter, center = true, $fn = 32);
        // Countersink (cone)
        translate([0, 0, thickness/2 - countersink_depth])
            cylinder(h = countersink_depth + 0.01, d1 = hole_diameter, d2 = countersink_diameter, $fn = 32);
    }
}

// Hole X positions (symmetric about center line, 10mm from left and right edges)
hole_x_positions = [edge_distance, flange_width - edge_distance];

difference() {
    union() {
        // Horizontal flange: extends in +Y direction, thickness in +Z at bottom (Z=0 to Z=thickness)
        // But inner corner at origin means the top surface of horizontal flange is at Z=0
        // So horizontal flange goes from Z=-thickness to Z=0, extending in +Y
        translate([0, 0, -thickness])
            cube([flange_width, flange_depth, thickness]);
        
        // Vertical flange: extends in +Z direction from origin, thickness in +Y at back
        // Inner corner at origin means inner surface is at Y=0
        // So vertical flange goes from Y=-thickness to Y=0, extending in +Z
        translate([0, -thickness, 0])
            cube([flange_width, thickness, flange_depth]);
    }
    
    // Countersunk holes on horizontal flange
    // Holes at Y = 10mm from edge (which is at Y=0, so Y = flange_depth - edge_distance from far edge)
    // Center of flange in Y direction, 10mm from the outer edge (Y = flange_depth)
    // So hole Y position = flange_depth - edge_distance
    for (x = hole_x_positions) {
        translate([x, flange_depth - edge_distance, -thickness/2])
            rotate([180, 0, 0])  // Countersink on bottom (-Z side, outside)
                countersunk_hole();
    }
    
    // Countersunk holes on vertical flange
    // 10mm from top edge (Z = flange_depth), so Z = flange_depth - edge_distance
    for (x = hole_x_positions) {
        translate([x, -thickness/2, flange_depth - edge_distance])
            rotate([-90, 0, 0])  // Countersink on -Y side (outside)
                countersunk_hole();
    }
}
```