fix: 🐛 Play mislabeled audio files on iOS/macOS

[lavigarg-simform]

Description

On iOS/macOS the file extension picks the audio parser. Android often records AAC-in-MP4 but names the file .mp3 or .aac. The extension lies, so AVFoundation grabs the wrong parser and the file fails to load (or silently mis-parses, e.g. a bogus 8ms duration).

What changed

• Before preparing the player, sniff the real container from the file's leading magic bytes.
• If the real container disagrees with the extension, point the player at a temp symlink that carries the correct extension, so the right parser is chosen.
• Detects MP4/M4A, WAV, FLAC, Ogg, MP3, and ADTS AAC.
• Done once in the Dart layer, so iOS, macOS, and the waveform extractor path are all covered without duplicating logic in the native players.
• If the bytes match nothing known, the path is left untouched — no behavior change for files that genuinely can't play.
• No-op on other platforms.

Checklist

• The title of my PR starts with a Conventional Commit prefix (fix:, feat:, docs: etc).
• I have followed the Contributor Guide when preparing my PR.
• I have updated/added tests for ALL new/updated/fixed functionality.
• I have updated/added relevant documentation in docs and added dartdoc comments with ///.
• I have updated/added relevant examples in examples or docs.

Breaking Change?

• Yes, this PR is a breaking change.
• No, this PR is not a breaking change.

Related Issues

Closes #113