add AI and generation routers, models, and OpenRouter service integration with tests

Co-authored-by: Copilot <copilot@github.com>

backend/app/services/openrouter.py

@@ -0,0 +1,123 @@
+"""OpenRouter API client (OpenAI-compatible interface)."""
+import os
+from typing import Any
+
+import httpx
+
+OPENROUTER_BASE_URL = "https://openrouter.ai/api/v1"
+
+
+def _api_key() -> str:
+    key = os.getenv("OPENROUTER_API_KEY")
+    if not key:
+        raise RuntimeError(
+            "OPENROUTER_API_KEY environment variable is not set.")
+    return key
+
+
+def _headers() -> dict[str, str]:
+    return {
+        "Authorization": f"Bearer {_api_key()}",
+        "Content-Type": "application/json",
+        "HTTP-Referer": os.getenv("APP_URL", "https://ai.allucanget.biz"),
+        "X-Title": os.getenv("APP_NAME", "AI Allucanget"),
+    }
+
+
+async def list_models() -> list[dict[str, Any]]:
+    """Return available models from OpenRouter."""
+    base_url = os.getenv("OPENROUTER_BASE_URL", OPENROUTER_BASE_URL)
+    async with httpx.AsyncClient(timeout=15) as client:
+        resp = client.build_request(
+            "GET", f"{base_url}/models", headers=_headers())
+        response = await client.send(resp)
+        response.raise_for_status()
+        return response.json().get("data", [])
+
+
+async def chat_completion(
+    model: str,
+    messages: list[dict[str, str]],
+    temperature: float = 0.7,
+    max_tokens: int = 1024,
+) -> dict[str, Any]:
+    """Send a chat completion request to OpenRouter."""
+    base_url = os.getenv("OPENROUTER_BASE_URL", OPENROUTER_BASE_URL)
+    payload = {
+        "model": model,
+        "messages": messages,
+        "temperature": temperature,
+        "max_tokens": max_tokens,
+    }
+    async with httpx.AsyncClient(timeout=60) as client:
+        response = await client.send(resp)
+        response.raise_for_status()
+        return response.json()
+
+
+async def generate_image(
+    model: str,
+    prompt: str,
+    n: int = 1,
+    size: str = "1024x1024",
+) -> dict[str, Any]:
+    """Request image generation via OpenRouter /images/generations."""
+    base_url = os.getenv("OPENROUTER_BASE_URL", OPENROUTER_BASE_URL)
+    payload = {"model": model, "prompt": prompt, "n": n, "size": size}
+    async with httpx.AsyncClient(timeout=120) as client:
+        resp = client.build_request(
+            "POST", f"{base_url}/images/generations", headers=_headers(), json=payload
+        )
+        response = await client.send(resp)
+        response.raise_for_status()
+        return response.json()
+
+
+async def generate_video(
+    model: str,
+    prompt: str,
+    duration_seconds: int | None = None,
+    aspect_ratio: str = "16:9",
+) -> dict[str, Any]:
+    """Request text-to-video generation via OpenRouter."""
+    base_url = os.getenv("OPENROUTER_BASE_URL", OPENROUTER_BASE_URL)
+    payload: dict[str, Any] = {
+        "model": model,
+        "prompt": prompt,
+        "aspect_ratio": aspect_ratio,
+    }
+    if duration_seconds is not None:
+        payload["duration_seconds"] = duration_seconds
+    async with httpx.AsyncClient(timeout=120) as client:
+        resp = client.build_request(
+            "POST", f"{base_url}/video/generations", headers=_headers(), json=payload
+        )
+        response = await client.send(resp)
+        response.raise_for_status()
+        return response.json()
+
+
+async def generate_video_from_image(
+    model: str,
+    image_url: str,
+    prompt: str,
+    duration_seconds: int | None = None,
+    aspect_ratio: str = "16:9",
+) -> dict[str, Any]:
+    """Request image-to-video generation via OpenRouter."""
+    base_url = os.getenv("OPENROUTER_BASE_URL", OPENROUTER_BASE_URL)
+    payload: dict[str, Any] = {
+        "model": model,
+        "image_url": image_url,
+        "prompt": prompt,
+        "aspect_ratio": aspect_ratio,
+    }
+    if duration_seconds is not None:
+        payload["duration_seconds"] = duration_seconds
+    async with httpx.AsyncClient(timeout=120) as client:
+        resp = client.build_request(
+            "POST", f"{base_url}/video/generations/from-image", headers=_headers(), json=payload
+        )
+        response = await client.send(resp)
+        response.raise_for_status()
+        return response.json()