feat: backend servis iskeletini ve yönetim uçlarını ekle

backend/app/llm/ollama_client.py

@@ -0,0 +1,37 @@
+import httpx
+from httpx import HTTPError
+
+from app.models import OllamaStatus
+
+class OllamaClient:
+    def __init__(self, base_url: str) -> None:
+        self.base_url = base_url.rstrip("/")
+
+    async def health(self) -> bool:
+        async with httpx.AsyncClient(timeout=5.0) as client:
+            response = await client.get(f"{self.base_url}/api/tags")
+        return response.is_success
+
+    async def status(self, model: str) -> OllamaStatus:
+        try:
+            async with httpx.AsyncClient(timeout=5.0) as client:
+                response = await client.get(f"{self.base_url}/api/tags")
+            response.raise_for_status()
+        except HTTPError as exc:
+            return OllamaStatus(
+                reachable=False,
+                base_url=self.base_url,
+                model=model,
+                message=f"Ollama unreachable: {exc}",
+            )
+
+        payload = response.json()
+        installed_models = [item.get("name", "") for item in payload.get("models", []) if item.get("name")]
+        has_model = model in installed_models
+        return OllamaStatus(
+            reachable=True,
+            base_url=self.base_url,
+            model=model,
+            installed_models=installed_models,
+            message="Model found." if has_model else "Ollama reachable but model is not installed.",
+        )