refactor: CI optimization, logging improvements, and codebase formatting (#456)

* fix(db): remove unique constraint on folder to support multi-channel agents

* ci: implement automated skill drift detection and self-healing PRs

* fix: align registration logic with Gavriel's feedback and fix build/test issues from Daniel Mi

* style: conform to prettier standards for CI validation

* test: fix branch naming inconsistency in CI (master vs main)

* fix(ci): robust module resolution by removing file extensions in scripts

* refactor(ci): simplify skill validation by removing redundant combination tests

* style: conform skills-engine to prettier, unify logging in index.ts and cleanup unused imports

* refactor: extract multi-channel DB changes to separate branch

Move channel column, folder suffix logic, and related migrations
to feat/multi-channel-db-v2 for independent review. This PR now
contains only CI/CD optimizations, Prettier formatting, and
logging improvements.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

skills-engine/migrate.ts

@@ -42,11 +42,7 @@ export function migrateExisting(): void {
 
     if (diff.trim()) {
       fs.mkdirSync(customDir, { recursive: true });
-      fs.writeFileSync(
-        path.join(projectRoot, patchRelPath),
-        diff,
-        'utf-8',
-      );
+      fs.writeFileSync(path.join(projectRoot, patchRelPath), diff, 'utf-8');
 
       // Extract modified file paths from the diff
       const filesModified = [...diff.matchAll(/^diff -ruN .+ (.+)$/gm)]