Progressive API / SDK 1.83 — explicit H.264 B-frame preview

SDK 1.83 adds an explicitly selected continuous-h264-reordered-video-v1 profile to FoxicMP Classic, Windows Qt and Linux Qt. The existing default continuous profile and SDK 1.82 payload remain unchanged.

Use ContinuousRemux(client, session_directory, mode=REORDERED_MODE) after checking the player capability. The new profile preserves H.264 B-frame presentation order without transcoding. Its current scope is one local video-only fast-start MP4, known duration, zero timestamp origin and confirmed SHA/ranges, within the advertised memory, byte and packet budgets. Audio, live and encrypted sources are outside this profile.

Included: standalone Python SDK, Windows Classic and Qt portable packages, Linux portable tarball and Debian package (0.2.0-183). These packages are required for this new profile; earlier application installers do not gain it by replacing only the Python SDK. Personal profiles are not included. Application version remains 0.2.0; SDK version is 1.83.

Validation covers all three editions, SDK 1.82 compatibility, explicit playback, pause/append/complete/seek/EOF, Stop, independent endpoints, files-closed receipts and final unpacked payloads. The clean SDK manifest records the exact source commit and every file checksum. See docs/ProgressiveReorderedSdk.md and the validation reports for scope and open acceptance items.

This is an integration prerelease, not full completion of the progressive playback specification. General audio/remux, longer stress tests and previously recorded latency outliers remain open. YouTubeHarvester is unchanged.