fix: prevent CPNP_NO from being overridden by dynamic column detection

CPNP_NO must stay hardcoded at index 107. Removed it from COLUMN_PATTERNS
and added guard to skip empty patterns in resolveColumnIndices.

Co-Authored-By: claude-flow <ruv@ruv.net>

src/types.ts

@@ -82,7 +82,7 @@ export const COLUMN_PATTERNS: Record<keyof typeof COLUMNS, string[]> = {
   ITEM_TO_LOGISTIC: ['item', 'logistic'],
   ANNA_CHECK: ['anna', 'check'],
   ANNA_NOTE: ['anna', 'note'],
-  CPNP_NO: ['cpnp'],
+  CPNP_NO: [],
   // Virtual/Extra columns stay hardcoded and are NOT auto-detected from headers
   // to prevent internal data from being shifted or overwritten by Excel column shifts.
 };
@@ -92,7 +92,8 @@ export function resolveColumnIndices(headers: string[]): typeof COLUMNS {
   const h = headers.map(val => String(val || '').toLowerCase());
 
   Object.entries(COLUMN_PATTERNS).forEach(([key, patterns]) => {
-    const idx = h.findIndex(headerText => 
+    if (patterns.length === 0) return;
+    const idx = h.findIndex(headerText =>
       patterns.every(p => headerText.includes(p.toLowerCase()))
     );
     if (idx >= 0) {