Add status=downloaded filter for model endpoint (#1539)

## Motivation

https://github.com/exo-explore/exo/issues/1346#issuecomment-3831427905


## Test Plan

### Manual Testing
**Without filter**
<img width="1708" height="1010" alt="Screenshot 2026-02-18 at 22 26 22"
src="https://github.com/user-attachments/assets/f4bf7142-717d-4042-ac28-d8a55a8e45e7"
/>

**With filter**
<img width="1723" height="1021" alt="Screenshot 2026-02-18 at 22 26 45"
src="https://github.com/user-attachments/assets/40a522d5-c6e6-4148-b21a-02caa1221ebe"
/>

src/exo/download/coordinator.py

@@ -123,14 +123,17 @@ class DownloadCoordinator:
                 tg.start_soon(self._check_internet_connection)
 
     def _test_internet_connection(self) -> None:
-        try:
-            socket.create_connection(("1.1.1.1", 443), timeout=3).close()
-            self.shard_downloader.set_internet_connection(True)
-        except OSError:
-            self.shard_downloader.set_internet_connection(False)
-        logger.debug(
-            f"Internet connectivity: {self.shard_downloader.internet_connection}"
-        )
+        # Try multiple endpoints since some ISPs/networks block specific IPs
+        for host in ("1.1.1.1", "8.8.8.8", "1.0.0.1"):
+            try:
+                socket.create_connection((host, 443), timeout=3).close()
+                self.shard_downloader.set_internet_connection(True)
+                logger.debug(f"Internet connectivity: True (via {host})")
+                return
+            except OSError:
+                continue
+        self.shard_downloader.set_internet_connection(False)
+        logger.debug("Internet connectivity: False")
 
     async def _check_internet_connection(self) -> None:
         first_connection = True

src/exo/master/api.py

@@ -145,6 +145,7 @@ from exo.shared.types.openai_responses import (
     ResponsesResponse,
 )
 from exo.shared.types.state import State
+from exo.shared.types.worker.downloads import DownloadCompleted
 from exo.shared.types.worker.instances import Instance, InstanceId, InstanceMeta
 from exo.shared.types.worker.shards import Sharding
 from exo.utils.banner import print_startup_banner
@@ -1292,8 +1293,18 @@ class API:
 
         return total_available
 
-    async def get_models(self) -> ModelList:
-        """Returns list of available models."""
+    async def get_models(self, status: str | None = Query(default=None)) -> ModelList:
+        """Returns list of available models, optionally filtered by being downloaded."""
+        cards = await get_model_cards()
+
+        if status == "downloaded":
+            downloaded_model_ids: set[str] = set()
+            for node_downloads in self.state.downloads.values():
+                for dl in node_downloads:
+                    if isinstance(dl, DownloadCompleted):
+                        downloaded_model_ids.add(dl.shard_metadata.model_card.model_id)
+            cards = [c for c in cards if c.model_id in downloaded_model_ids]
+
         return ModelList(
             data=[
                 ModelListModel(
@@ -1311,7 +1322,7 @@ class API:
                     base_model=card.base_model,
                     capabilities=card.capabilities,
                 )
-                for card in await get_model_cards()
+                for card in cards
             ]
         )