[fix] scrub fields: escape reverts typing, rows refresh after undo, one undo step per gesture (37 R26)

[AlexZ005]

Roadmap 37, item R26 (P1): the three scrub-field + undo bugs the 38 behaviour lock found (QUESTIONS-38-lock Q1-Q3).

What changed

• Q1: Escape after typing reverts. DragRow puts the box text back before the blur, and ignores the blur's change, so the typed value is no longer re-committed. It leaves no undo step.
• Q2: rows refresh after Ctrl+Z / Ctrl+Y. history.undo()/redo() poke selectedObject after any replay, so the Inspector's transform rows show the restored values at once.
• Q3: one undo step per scrub and per typed edit, in every scrub field. $lib/historyGesture.js (a leaf) holds the current gesture token. DragRow opens one per scrub and one per typing session; SliderRow opens one per range drag. history.recordEntry folds an entry into the stack top in place when both carry the same token (per-kind merges: transform, transformSet, aibatch, props, anim, the new animspeed, shadergraph; anything else becomes a gesture composite). A fold that nets to nothing is dropped.
• Shader editor: xyflow's view state (selected, dragging, measured, resizing) no longer goes into the replicated graph document (the nodesHandler.serializeNode rule). Clicking a node used to be an undoable, broadcast graph edit, and it was the second undo step on a shader-vector scrub.
• Newly undoable: Render order, light intensity and the other light values, and the Animation window's Speed.

Proof

• New suite scrub-undo: 156 PASS / 0 FAIL. It covers transforms, render order, light intensity, the light-distance slider and box, a shader vec2, and the Animation window's length, speed, fps and step: scrub, typed edit, slow typing, Escape, and the value shown right after undo.
• Counterfactuals, each piece reverted in turn (scrub-undo):
  • Q1 (original Escape code) → 28 red
  • Q2 (no refresh) → 24 red
  • Q3 (no fold) → 46 red
  • shader view keys kept → the original 2 reds
• Also green: shader-graph, undo, number-fields, animation-window, mesh-adjust, inspector, inspector-multi-edit, node-drag-fields.
• Two reds also fail identically on pristine 1.25.0, so they predate this PR: shader-editor (texture-decode check) and animation-curves (graph-key right-click).
• svelte-check 318/47 (= baseline), vitest 1544 green, npm run build green.

38 lock

The lock-dragrow flip (KNOWN Q1-Q3 → fixed) lives on feat/37-bugs-lock, for the redesign lanes to merge once 1.27 is in their base. See NOTES-38.

Do not merge from the lane; the 1.27 integrator merges.

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