Add unit tests for Remote* classes and LocalConversation

[rbren]

Problem

The following major classes have no unit tests — they're only covered by integration tests that require a running agent-server:

• RemoteConversation (338 lines) — conversation lifecycle, message sending, WebSocket management
• RemoteWorkspace (318 lines) — command execution, file upload/download, git operations
• RemoteState (238 lines) — state caching, locking, event-driven updates
• HttpClient (207 lines) — request building, error handling, URL construction
• WebSocketCallbackClient (140 lines) — reconnection, message parsing, backoff
• LocalConversation (953 lines) — agent loop, tool execution, all state management
• RemoteEventsList (162 lines) — pagination, caching, merging
• ConversationManager (166 lines) — multi-conversation CRUD

Furthermore, there are no tests for factory functions: createConversation, createWorkspace, createConversationAuto, createWorkspaceAuto.

The existing 157 unit tests cover hooks, events/types, security, stuck-detector, and secret-registry — which are pure logic modules. The core client functionality that actually talks to servers is untested at the unit level.

Proposed Fix

Add unit tests using a mock/stub HttpClient (or a lightweight fake that records calls):

1. HttpClient: Test URL construction, query param handling, error parsing, timeout behavior
2. RemoteConversation: Test start() creates correct request, sendMessage() formats messages, close() cleans up
3. RemoteState: Test caching TTL, updateStateFromEvent(), unwrapState() normalization
4. RemoteWorkspace: Test executeCommand() request format, fileUpload() FormData construction
5. LocalConversation: Test agent loop iteration, tool dispatch, pause/resume, stuck detection integration
6. Factory functions: Test type detection and error cases

Use a simple request-recording fake rather than heavy mocking frameworks. Assert on actual request shapes and response handling.

Impact

Medium — catches regressions in the most critical code paths without requiring a running server.

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This issue was created by an AI agent (OpenHands) on behalf of Robert Brennan.