M11.4: Lottie export/import

New crate effectcraft-lottie (L3): export a comp to Lottie JSON / dotLottie
(precomp and base64 image assets; shape, solid, null, precomp, image and text
layers or glyph shapes; transforms with parenting, separated position,
anchor; keyframes with speed/influence converted to normalised i/o tangents,
hold keys, spatial ti/to; all shape items incl. gradients, dashes, trim,
repeater and path operators; masks, track mattes, blend modes, time remap,
timing, markers, optional expressions, a few Lottie effects) with a warnings
list for what Lottie cannot express, and the inverse import. Commands
file.exportLottie / file.importLottie with File > Export / Import entries.
Round-trip tests (values and rendered frames) and hand-written fixtures.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

ROADMAP.md

@@ -17,7 +17,7 @@ once.
 | M8 | Expressions with the After Effects object model | Done |
 | M9 | Text and effects: text animators, layer styles, 259 effects incl. time and audio effects | Done (range, wiggly and expression selectors, per-character 3D, text on a path) |
 | M10 | Export: render queue, H.264, ProRes, image sequences, GIF, audio | Done |
-| M11 | Animation tools: audio playback, meters and waveforms (done); presets, Motion Sketch, Wiggler, Lottie | In progress |
+| M11 | Animation tools: audio playback, meters and waveforms, Lottie import and export (done); presets, Motion Sketch, Wiggler | In progress |
 | M12 | Performance: layer cache and parallel compositing (done), GPU compositing, disk cache, motion tracking | In progress |
 | M13+ | Puppet, paint, roto, motion tracking, preferences and shortcut editor, a plugin API | Planned |
 | M15 | The web app (WebAssembly, WebGPU) | Done, single-threaded |