v2.2.0

Added

• New "Image Sequence" export mode, alongside Video and Animated Image:
  each rendered frame is written as an individual image file rather than
  muxed into a video container, for direct import into an external
  compositing/editing pipeline. New ImageSequenceExportPipeline
  (Videotoy.Ffmpeg) launches one dedicated FFmpeg encode invocation per
  frame (-frames:v 1, not a single continuous stdin stream like the video/
  animated-image pipelines) — the deliberate reason being that this makes
  resuming an interrupted export trivial: already-encoded frame files are
  simply skipped
• Four sequence formats, all alpha-carrying: PNG 8-bit (-pix_fmt rgba),
  PNG 16-bit (-pix_fmt rgba64be), TIFF 16-bit with optional LZW
  compression (-pix_fmt rgba64le, -compression_algo lzw), and EXR 16-bit
  half-float (-pix_fmt gbrapf16le, not re-verified against a live
  ffmpeg.exe in this environment — see the code comment on
  FfmpegImageSequenceOptions). Scoping note: the render pipeline is
  currently 8-bit RGBA only (no HDR float render target — planned for
  v2.3.0), so the 16-bit PNG/TIFF and EXR formats are produced by
  bit-depth-expanding the existing 8-bit source, not genuine wider dynamic
  range; Domain.ImageSequenceFormat's doc comment states this plainly, and
  the written metadata JSON's colorspace note is honest about it too
  ("Linear half-float (expanded from 8-bit sRGB source — not true HDR; see v2.3.0)" for EXR)
• Configurable frame naming: a printf-style pattern (frame_%05d.png) or a
  token pattern ({index}/{time}, e.g. shot_{index}_{time}.png) via
  Domain.ImageSequenceNamingMode, validated to always contain a
  frame-distinguishing specifier/token (ImageSequenceExportSettingsValidator
  rejects a pattern that would make every frame overwrite the same file).
  Collision detection scans the output directory before starting; if
  matching frame files already exist, the render settings panel shows an
  inline confirmation prompt offering to resume or to overwrite
• Resume of an interrupted sequence export: when frame files already exist
  and the user chooses "Resume", already-encoded frame indices are skipped
  rather than re-rendered — the frame is still rendered (the deterministic
  renderer has no arbitrary-index resume API), only the FFmpeg
  encode/disk-write step is skipped, which stays far cheaper than the
  per-frame FFmpeg invocation it avoids
• A <sequence-name>.metadata.json file written in the output directory at
  the end of a successful export: resolution, FPS, first/last frame index
  actually written, colorspace note, alpha mode, and format — for import
  into external compositing/editing tools
• Integration with the render queue: RenderQueueItemKind.ImageSequence
  alongside the existing Video/AnimatedImage kinds, with its own
  persisted settings group in RenderQueueItem
• New Core modules: ImageSequenceExportSettingsValidator (validation,
  naming-pattern resolution/substitution, format/naming-mode key
  round-tripping) and ImageSequenceFileSizeEstimator (coarse per-format
  bytes-per-pixel estimate — PNG/TIFF/EXR have no bitrate/CRF concept, so
  this is intentionally coarser than the video estimator)