feat: allow returning embeddings and metadata from /vector_stores/ methods; disallow changing Provider ID (#4046)

# What does this PR do?

- Updates `/vector_stores/{vector_store_id}/files/{file_id}/content` to
allow returning `embeddings` and `metadata` using the `extra_query`
    -  Updates the UI accordingly to display them.

- Update UI to support CRUD operations in the Vector Stores section and
adds a new modal exposing the functionality.

- Updates Vector Store update to fail if a user tries to update Provider
ID (which doesn't make sense to allow)

```python
In  [1]: client.vector_stores.files.content(
    vector_store_id=vector_store.id, 
    file_id=file.id, 
    extra_query={"include_embeddings": True, "include_metadata": True}
)
Out [1]: FileContentResponse(attributes={}, content=[Content(text='This is a test document to check if embeddings are generated properly.\n', type='text', embedding=[0.33760684728622437, ...,], chunk_metadata={'chunk_id': '62a63ae0-c202-f060-1b86-0a688995b8d3', 'document_id': 'file-27291dbc679642ac94ffac6d2810c339', 'source': None, 'created_timestamp': 1762053437, 'updated_timestamp': 1762053437, 'chunk_window': '0-13', 'chunk_tokenizer': 'DEFAULT_TIKTOKEN_TOKENIZER', 'chunk_embedding_model': 'sentence-transformers/nomic
-ai/nomic-embed-text-v1.5', 'chunk_embedding_dimension': 768, 'content_token_count': 13, 'metadata_token_count': 9}, metadata={'filename': 'test-embedding.txt', 'chunk_id': '62a63ae0-c202-f060-1b86-0a688995b8d3', 'document_id': 'file-27291dbc679642ac94ffac6d2810c339', 'token_count': 13, 'metadata_token_count': 9})], file_id='file-27291dbc679642ac94ffac6d2810c339', filename='test-embedding.txt')
```

Screenshots of UI are displayed below:

### List Vector Store with Added "Create New Vector Store"
<img width="1912" height="491" alt="Screenshot 2025-11-06 at 10 47
25 PM"
src="https://github.com/user-attachments/assets/a3a3ddd9-758d-4005-ac9c-5047f03916f3"
/>

### Create New Vector Store
<img width="1918" height="1048" alt="Screenshot 2025-11-06 at 10 47
49 PM"
src="https://github.com/user-attachments/assets/b4dc0d31-696f-4e68-b109-27915090f158"
/>

### Edit Vector Store
<img width="1916" height="1355" alt="Screenshot 2025-11-06 at 10 48
32 PM"
src="https://github.com/user-attachments/assets/ec879c63-4cf7-489f-bb1e-57ccc7931414"
/>


### Vector Store Files Contents page (with Embeddings)
<img width="1914" height="849" alt="Screenshot 2025-11-06 at 11 54
32 PM"
src="https://github.com/user-attachments/assets/3095520d-0e90-41f7-83bd-652f6c3fbf27"
/>

### Vector Store Files Contents Details page (with Embeddings)
<img width="1916" height="1221" alt="Screenshot 2025-11-06 at 11 55
00 PM"
src="https://github.com/user-attachments/assets/e71dbdc5-5b49-472b-a43a-5785f58d196c"
/>

<!-- If resolving an issue, uncomment and update the line below -->
<!-- Closes #[issue-number] -->

## Test Plan
Tests added for Middleware extension and Provider failures.

---------

Signed-off-by: Francisco Javier Arceo <farceo@redhat.com>

src/llama_stack/core/library_client.py

@@ -389,6 +389,12 @@ class AsyncLlamaStackAsLibraryClient(AsyncLlamaStackClient):
         matched_func, path_params, route_path, webmethod = find_matching_route(options.method, path, self.route_impls)
         body |= path_params
 
+        # Pass through params that aren't already handled as path params
+        if options.params:
+            extra_query_params = {k: v for k, v in options.params.items() if k not in path_params}
+            if extra_query_params:
+                body["extra_query"] = extra_query_params
+
         body, field_names = self._handle_file_uploads(options, body)
 
         body = self._convert_body(matched_func, body, exclude_params=set(field_names))

src/llama_stack/core/routers/vector_io.py

@@ -247,6 +247,13 @@ class VectorIORouter(VectorIO):
         metadata: dict[str, Any] | None = None,
     ) -> VectorStoreObject:
         logger.debug(f"VectorIORouter.openai_update_vector_store: {vector_store_id}")
+
+        # Check if provider_id is being changed (not supported)
+        if metadata and "provider_id" in metadata:
+            current_store = await self.routing_table.get_object_by_identifier("vector_store", vector_store_id)
+            if current_store and current_store.provider_id != metadata["provider_id"]:
+                raise ValueError("provider_id cannot be changed after vector store creation")
+
         provider = await self.routing_table.get_provider_impl(vector_store_id)
         return await provider.openai_update_vector_store(
             vector_store_id=vector_store_id,
@@ -338,12 +345,19 @@ class VectorIORouter(VectorIO):
         self,
         vector_store_id: str,
         file_id: str,
+        include_embeddings: bool | None = False,
+        include_metadata: bool | None = False,
     ) -> VectorStoreFileContentResponse:
-        logger.debug(f"VectorIORouter.openai_retrieve_vector_store_file_contents: {vector_store_id}, {file_id}")
-        provider = await self.routing_table.get_provider_impl(vector_store_id)
-        return await provider.openai_retrieve_vector_store_file_contents(
+        logger.debug(
+            f"VectorIORouter.openai_retrieve_vector_store_file_contents: {vector_store_id}, {file_id}, "
+            f"include_embeddings={include_embeddings}, include_metadata={include_metadata}"
+        )
+
+        return await self.routing_table.openai_retrieve_vector_store_file_contents(
             vector_store_id=vector_store_id,
             file_id=file_id,
+            include_embeddings=include_embeddings,
+            include_metadata=include_metadata,
         )
 
     async def openai_update_vector_store_file(

src/llama_stack/core/routing_tables/vector_stores.py

@@ -195,12 +195,17 @@ class VectorStoresRoutingTable(CommonRoutingTableImpl):
         self,
         vector_store_id: str,
         file_id: str,
+        include_embeddings: bool | None = False,
+        include_metadata: bool | None = False,
     ) -> VectorStoreFileContentResponse:
         await self.assert_action_allowed("read", "vector_store", vector_store_id)
+
         provider = await self.get_provider_impl(vector_store_id)
         return await provider.openai_retrieve_vector_store_file_contents(
             vector_store_id=vector_store_id,
             file_id=file_id,
+            include_embeddings=include_embeddings,
+            include_metadata=include_metadata,
         )
 
     async def openai_update_vector_store_file(