[dvd233]

decomposeTransform() normalizes the matrix for an element's existing origin before calling setLocalTransform(). That call resets the origin to zero, so the next update reconstructs the matrix around the wrong point and a dragged element jumps.

Restore the saved origin after decomposition. Direct setLocalTransform() calls keep their existing origin-zero behavior.

Nonzero anchors retain their separate existing translation issue during decomposition; this change addresses the origin reset only.

Validation on Node 18.20.8:

• 87 unit tests across 13 suites passed, including 19 new cases covering rotation, nonuniform scale, skew, reflection, zero/one-axis origins, transformed parents and repeated drift. Tests check all six matrix entries and the direct setLocalTransform() contract.
• The first regression failed before the fix: the matrix's x-translation component was 102 instead of approximately 81.289. It passes after the fix.
• npm run lint passed.
• A separate actual exported Rect/Group public-API reproduction confirms the original offset and corrected matrices, with and without transformed parents. This does not exercise mouse dispatch or a complete renderer workflow.
• npm run release remains blocked by the pre-existing TS2683 at src/canvas/Painter.ts:1254 (this.dpr inside a callback). Painter, the TypeScript configuration and dependencies are unchanged; no build diagnostics were disabled.

The Windows Jest command uses the same test glob with forward slashes to avoid Jest 27's path-normalization issue with the .agent-storage parent. The test scope and TypeScript diagnostics are unchanged.

Fixes #1172.