refactor: move OpenCode artifacts under opencode/

arka/public is the dump for all Arka downloads. Keep a root stub so the
old installer URL still works. Document in-OpenCode bash install.

opencode/scripts/sync-catalog.py

@@ -0,0 +1,129 @@
+#!/usr/bin/env python3
+"""Rebuild catalog.json from the public arka-ai.ru OpenAI-compatible models list.
+
+Keep FORCED_MODELS / NON_CHAT in lockstep with opencode/plugins/arka-ai.ts.
+"""
+from __future__ import annotations
+
+import json
+import re
+import sys
+import urllib.request
+from datetime import datetime, timezone
+from pathlib import Path
+
+API_URL = "https://api.arka-ai.ru/v1/models"
+ROOT = Path(__file__).resolve().parents[1]
+OUT = ROOT / "catalog.json"
+
+FORCED_MODELS = [
+    "DeepSeek-V4-Pro",
+    "deepseek-v4-flash-0731",
+    "qwen3.8-max",
+    "kimi-k3",
+    "MiniMax-M3",
+    "GLM-5.3",
+]
+
+NON_CHAT = re.compile(
+    "|".join(
+        [
+            "tts",
+            "asr",
+            "audio",
+            "speech",
+            "voice",
+            "whisper",
+            "sensevoice",
+            "image",
+            r"(^|[.-])img",
+            "wan",
+            "vidu",
+            "video",
+            "sora",
+            "flux",
+            "diffus",
+            "kolors",
+            "cogview",
+            "ocr",
+            "embedding",
+            r"(^|[.-])embed",
+            "rerank",
+            "clip",
+            "moderation",
+            r"(^|[.-])filter",
+            "detect",
+            "classif",
+            r"(^|[.-])location",
+            r"(^|[.-])search",
+            "comfyui",
+            "meme",
+            "hello",
+            r"(^|[.-])sam",
+            "florence",
+            "esrgan",
+            "rmbg",
+            "background",
+            "poster",
+            r"(^|[.-])face",
+            r"(^|[.-])lip",
+            "translate",
+            r"(^|[.-])mt([2-]|$)",
+            r"(^|[.-])bge",
+            r"(^|[.-])e5",
+            r"(^|[.-])jina",
+            r"(^|[.-])mpnet",
+            "spark-tts",
+            "cosyvoice",
+            "chattts",
+            "indextts",
+            "step-audio",
+            "fish-speech",
+            "cosy",
+            "mate-gguf",
+            "tokenizer",
+        ]
+    ),
+    re.I,
+)
+
+
+def fetch_models() -> list[dict]:
+    req = urllib.request.Request(API_URL, headers={"User-Agent": "arka-public-catalog-sync"})
+    with urllib.request.urlopen(req, timeout=30) as resp:
+        payload = json.load(resp)
+    data = payload.get("data") or []
+    if not isinstance(data, list) or not data:
+        raise SystemExit("empty models list from api.arka-ai.ru")
+    return data
+
+
+def keep(item: dict) -> bool:
+    mid = item.get("id") or ""
+    return mid in FORCED_MODELS or not NON_CHAT.search(mid)
+
+
+def main() -> int:
+    raw = fetch_models()
+    chat = [item for item in raw if keep(item)]
+    chat.sort(key=lambda item: item.get("id") or "")
+    missing = [mid for mid in FORCED_MODELS if not any(item.get("id") == mid for item in chat)]
+    if missing:
+        print("warning: forced models missing from catalog:", ", ".join(missing), file=sys.stderr)
+
+    out = {
+        "updated_at": datetime.now(timezone.utc).strftime("%Y-%m-%dT%H:%M:%SZ"),
+        "source": API_URL,
+        "raw_count": len(raw),
+        "chat_count": len(chat),
+        "object": "list",
+        "data": [{"id": item.get("id"), "object": "model"} for item in chat],
+    }
+    text = json.dumps(out, ensure_ascii=False, indent=2) + "\n"
+    OUT.write_text(text, encoding="utf-8")
+    print(f"wrote {OUT} raw={out['raw_count']} chat={out['chat_count']}")
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())