feat: configure macOS video dimensions timeout

[itboy87]

macOS currently polls AVFoundation for video dimensions for five seconds. Valid remote media whose dimensions arrive later cannot opt into a longer window and may report Failed to retrieve video size.

This adds a positive, configurable dimension-polling timeout while retaining the existing 5,000 ms default, 250 ms polling cadence, duration polling, and initialization timeout. Desktop callers can use:

val playerState = rememberVideoPlayerState(macVideoDimensionsTimeoutMillis = 30_000L)

The setting is also available through DefaultVideoPlayerState(macVideoDimensionsTimeoutMillis = ...) and MacVideoPlayerState(videoDimensionsTimeoutMillis = ...). Existing no-argument constructors remain available. The desktop Compose overload disposes its state when removed or when the configured value changes; Windows and Linux retain their existing playback behavior.

Longer dimension polling stops when an open is superseded or the player is disposed. A superseded open cannot clear the current open's loading state.

Validation:

• Local JVM compilation and the full JVM suite passed: 76 tests passed, five skipped, no failures.
• Unit coverage verifies the unchanged five-second window and 20 reads, longer and shorter deadlines, positive dimensions, cancellation, superseded opens, invalid values, and no-argument constructors.
• Real AVFoundation tests use a synthetic MP4 behind a local HTTP server that delays responses by 16 seconds. The default still rejects the source; an explicit 30-second timeout plays both an MP4 URI and an opaque URI without reopening.
• A macOS CI job builds the JVM library and runs these unit and native integration tests with freshly built native binaries.