Expand 3D captcha into three subtypes: 3d_text, 3d_rotate, 3d_slider

Split the single "3d" captcha type into three independent expert models:
- 3d_text: 3D perspective text OCR (renamed from old "3d", CTC-based ThreeDCNN)
- 3d_rotate: rotation angle regression (new RegressionCNN, circular loss)
- 3d_slider: slider offset regression (new RegressionCNN, SmoothL1 loss)

CAPTCHA_TYPES expanded from 3 to 5 classes. Classifier samples updated
to 50000 (10000 per class). New generators, model, dataset, training
utilities, and full pipeline/export/CLI support for all subtypes.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

generators/threed_rotate_gen.py

@@ -0,0 +1,122 @@
+"""
+3D 旋转验证码生成器
+
+生成旋转验证码：圆盘上绘制字符 + 方向标记，随机旋转 0-359°。
+用户需将圆盘旋转到正确角度。
+
+标签 = 旋转角度（整数）
+文件名格式: {angle}_{index:06d}.png
+"""
+
+import random
+
+from PIL import Image, ImageDraw, ImageFilter, ImageFont
+
+from config import GENERATE_CONFIG, THREED_CHARS
+from generators.base import BaseCaptchaGenerator
+
+_FONT_PATHS = [
+    "/usr/share/fonts/TTF/DejaVuSans-Bold.ttf",
+    "/usr/share/fonts/TTF/DejaVuSerif-Bold.ttf",
+    "/usr/share/fonts/liberation/LiberationSans-Bold.ttf",
+    "/usr/share/fonts/liberation/LiberationSerif-Bold.ttf",
+    "/usr/share/fonts/gnu-free/FreeSansBold.otf",
+]
+
+_DISC_COLORS = [
+    (180, 200, 220),
+    (200, 220, 200),
+    (220, 200, 190),
+    (200, 200, 220),
+    (210, 210, 200),
+]
+
+
+class ThreeDRotateGenerator(BaseCaptchaGenerator):
+    """3D 旋转验证码生成器。"""
+
+    def __init__(self, seed: int | None = None):
+        from config import RANDOM_SEED
+        super().__init__(seed=seed if seed is not None else RANDOM_SEED)
+
+        self.cfg = GENERATE_CONFIG["3d_rotate"]
+        self.chars = THREED_CHARS
+        self.width, self.height = self.cfg["image_size"]
+
+        self._fonts: list[str] = []
+        for p in _FONT_PATHS:
+            try:
+                ImageFont.truetype(p, 20)
+                self._fonts.append(p)
+            except OSError:
+                continue
+        if not self._fonts:
+            raise RuntimeError("未找到任何可用字体，无法生成验证码")
+
+    def generate(self, text: str | None = None) -> tuple[Image.Image, str]:
+        rng = self.rng
+
+        # 随机旋转角度 0-359
+        angle = rng.randint(0, 359)
+
+        if text is None:
+            text = str(angle)
+
+        # 1. 背景
+        bg_val = rng.randint(*self.cfg["bg_color_range"])
+        img = Image.new("RGB", (self.width, self.height), (bg_val, bg_val, bg_val))
+        draw = ImageDraw.Draw(img)
+
+        # 2. 绘制圆盘
+        cx, cy = self.width // 2, self.height // 2
+        r = self.cfg["disc_radius"]
+        disc_color = rng.choice(_DISC_COLORS)
+        draw.ellipse(
+            [cx - r, cy - r, cx + r, cy + r],
+            fill=disc_color, outline=(100, 100, 100), width=2,
+        )
+
+        # 3. 在圆盘上绘制字符和方向标记 (未旋转状态)
+        disc_img = Image.new("RGBA", (r * 2 + 4, r * 2 + 4), (0, 0, 0, 0))
+        disc_draw = ImageDraw.Draw(disc_img)
+        dc = r + 2  # disc center
+
+        # 字符 (圆盘中心)
+        font_path = rng.choice(self._fonts)
+        font_size = int(r * 0.6)
+        font = ImageFont.truetype(font_path, font_size)
+        ch = rng.choice(self.chars)
+        bbox = font.getbbox(ch)
+        tw = bbox[2] - bbox[0]
+        th = bbox[3] - bbox[1]
+        disc_draw.text(
+            (dc - tw // 2 - bbox[0], dc - th // 2 - bbox[1]),
+            ch, fill=(50, 50, 50, 255), font=font,
+        )
+
+        # 方向标记 (三角箭头，指向上方)
+        ms = self.cfg["marker_size"]
+        marker_y = dc - r + ms + 2
+        disc_draw.polygon(
+            [(dc, marker_y - ms), (dc - ms // 2, marker_y), (dc + ms // 2, marker_y)],
+            fill=(220, 60, 60, 255),
+        )
+
+        # 4. 旋转圆盘内容
+        disc_img = disc_img.rotate(-angle, resample=Image.BICUBIC, expand=False)
+
+        # 5. 粘贴到背景
+        paste_x = cx - dc
+        paste_y = cy - dc
+        img.paste(disc_img, (paste_x, paste_y), disc_img)
+
+        # 6. 添加少量噪点
+        for _ in range(rng.randint(20, 50)):
+            nx, ny = rng.randint(0, self.width - 1), rng.randint(0, self.height - 1)
+            nc = tuple(rng.randint(100, 200) for _ in range(3))
+            draw.point((nx, ny), fill=nc)
+
+        # 7. 轻微模糊
+        img = img.filter(ImageFilter.GaussianBlur(radius=0.5))
+
+        return img, text