[sarthakagrawal927]

Part of #26.

Changes

• Add SDK room lifecycle coverage for socket open/close, reconnect scheduling, ping handling, and backpressure behavior using a fake EventTarget socket.
• Keep the tests network-independent and avoid changes to runtime behavior.

Verification

• pnpm check passed, including formatting, lint, typecheck, 85 tests, production build, and the repository's code-health gates.
• Focused pnpm exec vitest run web/src/sdk/room.test.ts passed (3 tests).

Remaining acceptance for #26

• This is one coverage increment. The broader TypeScript coverage target, remaining Periphery findings, iOS coverage, and camera/ReplayKit/device qualification remain open under Reduce code-health baseline debt #26.
• No deploy or device qualification was run.