fix(gap-audit): check .js files and account for dynamically loaded prompts

The gap audit was falsely reporting prompts as orphaned because:
1. grepImports() only checked .ts files, but extension source is .js
2. Several prompts loaded dynamically (not via literal loadPrompt string)
   were not in the DYNAMICALLY_LOADED_PROMPTS set

Fixes:
- grepImports now checks both .ts and .js files
- Added heal-skill, product-audit, refine-slice, review-migration to
  DYNAMICALLY_LOADED_PROMPTS set

This eliminates the false-positive orphan-prompt self-feedback entries.

src/resources/extensions/sf/gap-audit.js

@@ -41,7 +41,7 @@ function grepImports(sourceDir, symbol) {
 	try {
 		const files = readdirSync(sourceDir, { recursive: true });
 		for (const file of files) {
-			if (!file.endsWith(".ts")) continue;
+			if (!file.endsWith(".ts") && !file.endsWith(".js")) continue;
 			const content = readFileSync(join(sourceDir, file), "utf-8");
 			if (content.includes(symbol)) return true;
 		}
@@ -61,6 +61,10 @@ const DYNAMICALLY_LOADED_PROMPTS = new Set([
 	"execute-task",
 	"workflow-start",
 	"triage-self-feedback",
+	"heal-skill",
+	"product-audit",
+	"refine-slice",
+	"review-migration",
 ]);
 function findOrphanPrompts() {
 	const findings = [];