24 server tests passing, race-free

[opencode-agent]

All 24 tests pass clean (including -race). Created server/websocket_test.go with:

• sanitizeInput (8 tests): normal text, ANSI stripping, control char removal, newline/tab preservation, whitespace trimming, empty/whitespace-only input, unicode
• defaultColorForNick (3 tests): determinism, valid palette colors for various nicks including empty string
• broadcastToRoom (6 tests): message delivery to all clients, history accumulation, history cap at 30, slow client drop, non-existent room no-op, non-message types not recorded in history
• cleanupClient (7 tests): client removal, host transfer to oldest remaining client, empty room deletion, leave message broadcast, host transfer message broadcast, no host transfer on empty room, host unchanged when non-host leaves

Uses standard testing package with channel-based fake clients for broadcastToRoom and httptest-backed real websocket connections for cleanupClient. Follows existing project conventions (t.Fatal/t.Fatalf assertions, no external libraries).

Closes #2

opencode session  |  github run