fix: unexport internal DlpPattern interface in src/dlp.ts (#2437)

* Initial plan

* fix: remove export from internal DlpPattern interface in src/dlp.ts

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Co-authored-by: lpcox <15877973+lpcox@users.noreply.github.com>

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Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: lpcox <15877973+lpcox@users.noreply.github.com>

Author: Copilot

src/dlp.ts

@@ -15,7 +15,7 @@
 /**
  * A DLP credential pattern definition
  */
-export interface DlpPattern {
+interface DlpPattern {
   /** Human-readable name for the pattern */
   name: string;
   /** Description of what this pattern detects */