## ADDED Requirements

### Requirement: Proxy endpoint exists for running instances
The API SHALL expose an endpoint that forwards HTTP requests to a running tool instance.

#### Scenario: Access running instance
- **WHEN** an authenticated user sends a GET request to `/instances/{id}/proxy/`
- **THEN** the request is forwarded to the instance's container
- **AND** the response is returned to the user

#### Scenario: Access instance subpath
- **WHEN** an authenticated user sends a request to `/instances/{id}/proxy/api/status`
- **THEN** the request is forwarded to `{container_url}/api/status`
- **AND** the response is returned to the user

### Requirement: Only instance owner can access proxy
The proxy endpoint SHALL verify that the authenticated user owns the instance before forwarding.

#### Scenario: Owner accesses instance
- **WHEN** the instance owner requests `/instances/{id}/proxy/`
- **THEN** the request is forwarded to the instance

#### Scenario: Non-owner attempts access
- **WHEN** a user who does not own the instance requests `/instances/{id}/proxy/`
- **THEN** the API returns 403 Forbidden

### Requirement: Proxy handles WebSocket upgrades
The proxy endpoint SHALL support WebSocket upgrade requests for real-time features.

#### Scenario: WebSocket connection to instance
- **WHEN** a user sends a request with `Upgrade: websocket` header
- **THEN** the API establishes a bidirectional WebSocket connection to the instance
- **AND** messages are relayed between user and instance

### Requirement: Frontend uses proxy URL for instance access
The frontend SHALL link to the proxy endpoint instead of the internal container URL.

#### Scenario: User clicks Open button
- **WHEN** a user clicks "Open" on a running instance
- **THEN** a new tab opens to `/instances/{id}/proxy/`
- **AND** the proxied instance content is displayed