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>

src/services/enhanced-config-validator.ts

@@ -1209,30 +1209,30 @@ export class EnhancedConfigValidator extends ConfigValidator {
         'empty', 'notEmpty', 'equals', 'notEquals',
         'contains', 'notContains', 'startsWith', 'notStartsWith',
         'endsWith', 'notEndsWith', 'regex', 'notRegex',
-        'exists', 'notExists', 'isNotEmpty' // exists checks field presence, isNotEmpty alias for notEmpty
+        'exists', 'notExists'
       ],
       number: [
         'empty', 'notEmpty', 'equals', 'notEquals', 'gt', 'lt', 'gte', 'lte',
-        'exists', 'notExists', 'isNotEmpty'
+        'exists', 'notExists'
       ],
       dateTime: [
         'empty', 'notEmpty', 'equals', 'notEquals', 'after', 'before', 'afterOrEquals', 'beforeOrEquals',
-        'exists', 'notExists', 'isNotEmpty'
+        'exists', 'notExists'
       ],
       boolean: [
         'empty', 'notEmpty', 'true', 'false', 'equals', 'notEquals',
-        'exists', 'notExists', 'isNotEmpty'
+        'exists', 'notExists'
       ],
       array: [
         'contains', 'notContains', 'lengthEquals', 'lengthNotEquals',
         'lengthGt', 'lengthLt', 'lengthGte', 'lengthLte', 'empty', 'notEmpty',
-        'exists', 'notExists', 'isNotEmpty'
+        'exists', 'notExists'
       ],
       object: [
         'empty', 'notEmpty',
-        'exists', 'notExists', 'isNotEmpty'
+        'exists', 'notExists'
       ],
-      any: ['exists', 'notExists', 'isNotEmpty']
+      any: ['exists', 'notExists']
     };
 
     for (let i = 0; i < conditions.length; i++) {