[liviaUeno]

Summary

Reduces ESLint errors from 61 to 20 with changes that do not need a product or legal decision.

• Apply ESLint auto-fixes (import order, redundant JSX braces, type-only imports, duplicate imports, JSX tag spacing). No behavior change.
• Remove an unused _t import and add an explicit return type to useIsAdmin.
• Read window size from UIStore instead of window.innerWidth/innerHeight (VodsDrawer, LiveStreamWidget), as required by no-restricted-properties.
• Satisfy react-hooks/exhaustive-deps in the LiveStreamWidget HLS effect by depending on a local liveUrl, so the player is still recreated only when the URL changes.
• Rename the destructured playback_url to playbackUrl in SecurityRoomSettingsTab (the API field is unchanged).

Still failing (not in this PR)

• 20 × matrix-org/require-copyright-header on fork-created files: waiting for the header text to use.

Verification

pnpm -r lint:js: 61 → 20 errors, all require-copyright-header.