fix: correct operator names, connection types, and implement __patch_find_replace (#665, #659, #642) (#672)

Three critical fixes in n8n_update_partial_workflow:

- **#665**: Replace incorrect `isNotEmpty`/`isEmpty` operator names with `notEmpty`/`empty`
  across validators, sanitizer, docs, and error messages. Add auto-correction in sanitizer.
  Unknown operators silently returned false in n8n's execution engine.

- **#659**: Remap numeric `targetInput` values (e.g., "0") to "main" in addConnection.
  Relax sourceOutput remapping guard for redundant sourceOutput+sourceIndex combinations.
  Also resolves #653 (dangling connections caused by malformed type:"0" connections).

- **#642**: Implement __patch_find_replace for surgical string edits in updateNode.
  Previously stored patch objects literally as jsCode, producing [object Object].
  Now reads current value, applies find/replace sequentially, writes back the string.

Conceived by Romuald Członkowski - https://www.aiadvisors.pl/en

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

dist/services/workflow-diff-engine.d.ts

@@ -47,6 +47,7 @@ export declare class WorkflowDiffEngine {
     private normalizeNodeName;
     private findNode;
     private formatNodeNotFoundError;
+    private getNestedProperty;
     private setNestedProperty;
 }
 //# sourceMappingURL=workflow-diff-engine.d.ts.map