test(tui): cover WSTransport write paths, peer label, and handle_ws lifecycle (#36617)

[rodboev]

Fixes #36617

Summary

Current main already covers MCP startup, disconnect teardown, and stalled-loop recovery for tui_gateway/ws.py, so the older branch description was no longer accurate. The remaining gap was the coalesced transport path: buffered streaming frames, _safe_send_many, batch-send failure, and close-time timer cancellation. The branch also patched only server, even though handle_ws directly imports and calls start_background_mcp_discovery.

This refresh rebuilds the PR on current main, consolidates the surviving coverage into tests/test_tui_gateway_ws.py, applies one shared MCP-startup patch across every handle_ws case, and adds assertions that distinguish the buffered _safe_send_many path from the old direct-send transport.

Changes

• tests/test_tui_gateway_ws.py (+248/-41): add shared MCP-startup patching, prove buffered _safe_send_many batching, cover batch-send failure and timer cancellation, and keep the current-main handle_ws lifecycle cases in one module.
• tests/tui_gateway/test_ws.py (-225): remove the duplicate older module after its surviving cases were consolidated into the current-main test file.

Validation

Scenario	Before	After
Two streaming frames followed by a control frame	only direct-send ordering was covered	test proves buffered tokens flush through one _safe_send_many batch before the control frame
_safe_send_many failure mid-batch	untested	covered, transport latches closed and later frames are not sent
close() with an armed token flush timer	untested	covered, timer is cancelled and the handle is cleared
handle_ws startup side effect in test cases	only server was patched in the added cases	every handle_ws case runs under the shared start_background_mcp_discovery patch

Test plan

• pytest tests/test_tui_gateway_ws.py -v — 18 passed
• ruff check tests/test_tui_gateway_ws.py — passed

[teknium1]

Thanks for adding focused WebSocket coverage. This needs a current-main refresh before it can be salvaged.

Problems

• tests/tui_gateway/test_ws.py:116 patches only tui_gateway.ws.server, while current handle_ws directly imports and invokes start_background_mcp_discovery at tui_gateway/ws.py:312-317. These tests would mutate the shared MCP-startup guard (hermes_cli/mcp_startup.py:31-50) and can start real background discovery.
• Current WSTransport now coalesces streaming frames and sends via _safe_send_many (tui_gateway/ws.py:97-104, 125-159, 193-207). The proposed tests cover the earlier simple write paths but not batching, ordering, batch-send failure, or flush cancellation.

Suggested changes

• Add a shared patch for hermes_cli.mcp_startup.start_background_mcp_discovery, modeled on tests/test_tui_gateway_ws.py:10-42.
• Extend coverage for the current coalescing and teardown contracts; existing lifecycle coverage is in tests/test_tui_gateway_ws.py:90-164.

Automated hermes-sweeper review.