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/manifest.ts

@@ -39,7 +39,9 @@ export function readManifest(skillDir: string): SkillManifest {
   const allPaths = [...manifest.adds, ...manifest.modifies];
   for (const p of allPaths) {
     if (p.includes('..') || path.isAbsolute(p)) {
-      throw new Error(`Invalid path in manifest: ${p} (must be relative without "..")`);
+      throw new Error(
+        `Invalid path in manifest: ${p} (must be relative without "..")`,
+      );
     }
   }
 
@@ -78,7 +80,10 @@ export function checkSystemVersion(manifest: SkillManifest): {
   if (!manifest.min_skills_system_version) {
     return { ok: true };
   }
-  const cmp = compareSemver(manifest.min_skills_system_version, SKILLS_SCHEMA_VERSION);
+  const cmp = compareSemver(
+    manifest.min_skills_system_version,
+    SKILLS_SCHEMA_VERSION,
+  );
   if (cmp > 0) {
     return {
       ok: false,