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_slider_gen.py

@@ -0,0 +1,113 @@
+"""
+3D 滑块验证码生成器
+
+生成滑块拼图验证码：纹理背景 + 拼图缺口 + 拼图块在左侧。
+用户需将拼图块滑动到缺口位置。
+
+标签 = 缺口 x 坐标偏移（整数）
+文件名格式: {offset}_{index:06d}.png
+"""
+
+import random
+
+from PIL import Image, ImageDraw, ImageFilter
+
+from config import GENERATE_CONFIG
+from generators.base import BaseCaptchaGenerator
+
+
+class ThreeDSliderGenerator(BaseCaptchaGenerator):
+    """3D 滑块验证码生成器。"""
+
+    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_slider"]
+        self.width, self.height = self.cfg["image_size"]
+
+    def generate(self, text: str | None = None) -> tuple[Image.Image, str]:
+        rng = self.rng
+        pw, ph = self.cfg["puzzle_size"]
+        gap_x_lo, gap_x_hi = self.cfg["gap_x_range"]
+
+        # 缺口位置
+        gap_x = rng.randint(gap_x_lo, gap_x_hi)
+        gap_y = rng.randint(10, self.height - ph - 10)
+
+        if text is None:
+            text = str(gap_x)
+
+        # 1. 生成纹理背景
+        img = self._textured_background(rng)
+
+        # 2. 从缺口位置截取拼图块内容
+        piece_content = img.crop((gap_x, gap_y, gap_x + pw, gap_y + ph)).copy()
+
+        # 3. 绘制缺口 (半透明灰色区域)
+        overlay = Image.new("RGBA", img.size, (0, 0, 0, 0))
+        overlay_draw = ImageDraw.Draw(overlay)
+        overlay_draw.rectangle(
+            [gap_x, gap_y, gap_x + pw, gap_y + ph],
+            fill=(80, 80, 80, 160),
+            outline=(60, 60, 60, 200),
+            width=2,
+        )
+        img = img.convert("RGBA")
+        img = Image.alpha_composite(img, overlay)
+        img = img.convert("RGB")
+
+        # 4. 绘制拼图块在左侧
+        piece_x = self.cfg["piece_left_margin"]
+        piece_img = Image.new("RGBA", (pw + 4, ph + 4), (0, 0, 0, 0))
+        piece_draw = ImageDraw.Draw(piece_img)
+        # 阴影
+        piece_draw.rectangle([2, 2, pw + 3, ph + 3], fill=(0, 0, 0, 80))
+        # 内容
+        piece_img.paste(piece_content, (0, 0))
+        # 边框
+        piece_draw.rectangle([0, 0, pw - 1, ph - 1], outline=(255, 255, 255, 200), width=2)
+
+        img_rgba = img.convert("RGBA")
+        img_rgba.paste(piece_img, (piece_x, gap_y), piece_img)
+        img = img_rgba.convert("RGB")
+
+        # 5. 轻微模糊
+        img = img.filter(ImageFilter.GaussianBlur(radius=0.3))
+
+        return img, text
+
+    def _textured_background(self, rng: random.Random) -> Image.Image:
+        """生成带纹理的彩色背景。"""
+        img = Image.new("RGB", (self.width, self.height))
+        draw = ImageDraw.Draw(img)
+
+        # 渐变底色
+        base_r, base_g, base_b = rng.randint(100, 180), rng.randint(100, 180), rng.randint(100, 180)
+        for y in range(self.height):
+            ratio = y / max(self.height - 1, 1)
+            r = int(base_r + 30 * ratio)
+            g = int(base_g - 20 * ratio)
+            b = int(base_b + 10 * ratio)
+            draw.line([(0, y), (self.width, y)], fill=(r, g, b))
+
+        # 添加纹理噪声
+        noise_intensity = self.cfg["bg_noise_intensity"]
+        for _ in range(self.width * self.height // 8):
+            x = rng.randint(0, self.width - 1)
+            y = rng.randint(0, self.height - 1)
+            pixel = img.getpixel((x, y))
+            noise = tuple(
+                max(0, min(255, c + rng.randint(-noise_intensity, noise_intensity)))
+                for c in pixel
+            )
+            draw.point((x, y), fill=noise)
+
+        # 随机色块 (模拟图案)
+        for _ in range(rng.randint(3, 6)):
+            x1, y1 = rng.randint(0, self.width - 30), rng.randint(0, self.height - 20)
+            x2, y2 = x1 + rng.randint(15, 40), y1 + rng.randint(10, 25)
+            color = tuple(rng.randint(60, 220) for _ in range(3))
+            draw.rectangle([x1, y1, x2, y2], fill=color)
+
+        return img