fix(test): add textBetween/nodesBetween to remap-length tr.doc mock (#2834)

Same root cause as the other three files — the word-diff trim in
executor.ts calls tr.doc.textBetween and charOffsetToDocPos (which
uses tr.doc.nodesBetween). The remap-length mock needs:
- textBetween returning a range-sized unique string (no common
  prefix/suffix with any replacement) so the trim is a no-op
- nodesBetween simulating a single text node so charOffsetToDocPos
  maps offsets correctly

Author: caio-pizzol

packages/super-editor/src/editors/v1/document-api-adapters/plan-engine/remap-length.test.ts

@@ -123,6 +123,10 @@ function makeTr() {
     docChanged: true,
     doc: {
       resolve: () => ({ marks: () => [] }),
+      textBetween: vi.fn((from: number, to: number) => '\x01'.repeat(to - from)),
+      nodesBetween: vi.fn((from: number, to: number, cb: (node: any, pos: number) => void) => {
+        cb({ isText: true, nodeSize: to - from }, from);
+      }),
     },
   };
   tr.replaceWith.mockReturnValue(tr);