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]>

docs/agents.md

@@ -95,8 +95,15 @@ effectcraft-cli get Main '#1' transform/position --time 0.5 main.ecproj --json
 effectcraft-cli run main.ecproj comp.open '{"comp":"Main"}' time.set '{"time":1}' --json
 effectcraft-cli render-frame main.ecproj --time 1 --max-side 640 --out f.png --json
 effectcraft-cli exec layer.newNull --bridge 9877                 # same commands, against the live app
+effectcraft-cli exec file.exportLottie '{"comp":"Main","path":"main.json","includeExpressions":true}' main.ecproj --json
+effectcraft-cli exec file.importLottie '{"path":"anim.json"}' main.ecproj --save
 ```
 
+`file.exportLottie` returns `{path, bytes, warnings}`: the warnings list every feature Lottie
+cannot express (most effects, cameras and lights, layer styles, audio, video footage…), so an
+agent can check what a player will not show. A `.lottie` path writes a dotLottie archive.
+`file.importLottie` returns `{comp, items, warnings}` and opens the new composition.
+
 `<comp>` is an id or name, or `-` for the active comp. `<value>` is JSON (`50`, `[960,540]`,
 `"#ff0000"`) or a bare string.