feat: wire hybrid provider into CLI

src/javis/providers/ollama.py

@@ -4,6 +4,7 @@ from __future__ import annotations
 
 import json
 import socket
+from dataclasses import dataclass
 from urllib.error import HTTPError, URLError
 from urllib.request import Request, urlopen
 
@@ -17,14 +18,40 @@ from javis.providers.base import (
 )
 
 
+@dataclass(frozen=True, slots=True)
+class OllamaStatus:
+    reachable: bool
+    model_available: bool
+
+
 class OllamaProvider:
     name = "ollama"
 
     def __init__(self, model: str, base_url: str, timeout_seconds: float) -> None:
         self.model = model
-        self._endpoint = f"{base_url.rstrip('/')}/api/chat"
+        self._base_url = base_url.rstrip("/")
+        self._endpoint = f"{self._base_url}/api/chat"
         self._timeout_seconds = timeout_seconds
 
+    def probe(self) -> OllamaStatus:
+        request = Request(f"{self._base_url}/api/tags", method="GET")
+        try:
+            with urlopen(request, timeout=min(self._timeout_seconds, 3)) as response:
+                result = json.loads(response.read())
+        except (HTTPError, URLError, TimeoutError, OSError, json.JSONDecodeError):
+            return OllamaStatus(False, False)
+        models = result.get("models")
+        if not isinstance(models, list):
+            return OllamaStatus(True, False)
+        names = {
+            value
+            for item in models
+            if isinstance(item, dict)
+            for value in (item.get("name"), item.get("model"))
+            if isinstance(value, str)
+        }
+        return OllamaStatus(True, self.model in names)
+
     def chat(self, messages: list[ChatMessage]) -> str:
         payload = {
             "model": self.model,