Align task API and add FunCaptcha support

inference/model_metadata.py

@@ -0,0 +1,33 @@
+"""
+ONNX 模型 sidecar metadata 辅助工具。
+"""
+
+from __future__ import annotations
+
+import json
+from pathlib import Path
+
+
+def model_metadata_path(model_path: str | Path) -> Path:
+    return Path(model_path).with_suffix(".meta.json")
+
+
+def write_model_metadata(model_path: str | Path, metadata: dict) -> Path:
+    path = model_metadata_path(model_path)
+    payload = {
+        "version": 1,
+        **metadata,
+    }
+    path.parent.mkdir(parents=True, exist_ok=True)
+    with path.open("w", encoding="utf-8") as f:
+        json.dump(payload, f, ensure_ascii=True, indent=2, sort_keys=True)
+        f.write("\n")
+    return path
+
+
+def load_model_metadata(model_path: str | Path) -> dict | None:
+    path = model_metadata_path(model_path)
+    if not path.exists():
+        return None
+    with path.open("r", encoding="utf-8") as f:
+        return json.load(f)