fix: address code review findings from refactoring

- Remove dead parse() override in ExpressRouteDetector (never called
  since detect() delegates to detectWithRegex via AbstractTypeScriptDetector)
- Make extractClassName() static in AbstractJavaMessagingDetector
  (uses no instance state)
- Add cache versioning to AnalysisCache: cache_meta table tracks schema
  version, auto-clears stale caches on upgrade (e.g. MD5→SHA-256 hash
  change). Only clears and logs when upgrading from a known older version,
  not for fresh databases.

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

Author: aksOps

src/main/java/io/github/randomcodespace/iq/cache/AnalysisCache.java

@@ -38,7 +38,15 @@ public class AnalysisCache implements Closeable {
 
     private static final Logger log = LoggerFactory.getLogger(AnalysisCache.class);
 
+    /** Bump when hash algorithm or schema changes to force cache invalidation. */
+    private static final int CACHE_VERSION = 2;
+
     private static final String SCHEMA_SQL = """
+            CREATE TABLE IF NOT EXISTS cache_meta (
+                meta_key VARCHAR PRIMARY KEY,
+                meta_value VARCHAR NOT NULL
+            );
+
             CREATE TABLE IF NOT EXISTS files (
                 content_hash VARCHAR PRIMARY KEY,
                 path VARCHAR NOT NULL,
@@ -114,6 +122,35 @@ private void initDb() throws SQLException {
                 }
             }
         }
+        checkCacheVersion();
+    }
+
+    /**
+     * If the cache was created with a different version (e.g. MD5 vs SHA-256 hashes),
+     * clear all cached data so files are re-analyzed with the current algorithm.
+     */
+    private void checkCacheVersion() throws SQLException {
+        String storedVersion = null;
+        try (var ps = conn.prepareStatement("SELECT meta_value FROM cache_meta WHERE meta_key = 'version'");
+             var rs = ps.executeQuery()) {
+            if (rs.next()) {
+                storedVersion = rs.getString(1);
+            }
+        }
+        if (!String.valueOf(CACHE_VERSION).equals(storedVersion)) {
+            if (storedVersion != null) {
+                log.info("Cache version mismatch (stored={}, current={}) — clearing stale cache",
+                        storedVersion, CACHE_VERSION);
+                try (var stmt = conn.createStatement()) {
+                    stmt.execute("DELETE FROM edges");
+                    stmt.execute("DELETE FROM nodes");
+                    stmt.execute("DELETE FROM files");
+                }
+            }
+            try (var stmt = conn.createStatement()) {
+                stmt.execute("MERGE INTO cache_meta (meta_key, meta_value) VALUES ('version', '" + CACHE_VERSION + "')");
+            }
+        }
     }
 
     // --- Commit tracking ---

src/main/java/io/github/randomcodespace/iq/detector/java/AbstractJavaMessagingDetector.java

@@ -22,7 +22,7 @@ public abstract class AbstractJavaMessagingDetector extends AbstractRegexDetecto
      * Extract the first class name from the source text.
      * Returns null if no class is found.
      */
-    protected String extractClassName(String text) {
+    protected static String extractClassName(String text) {
         String[] lines = text.split("\n", -1);
         for (String line : lines) {
             Matcher cm = CLASS_RE.matcher(line);

src/main/java/io/github/randomcodespace/iq/detector/typescript/ExpressRouteDetector.java

@@ -44,11 +44,6 @@ public String getName() {
         return "typescript.express_routes";
     }
 
-    @Override
-    protected ParseTree parse(DetectorContext ctx) {
-        // Not called when detect() is overridden, kept for potential future use
-        return null;
-    }
 
     @Override
     protected DetectorResult detectWithAst(ParseTree tree, DetectorContext ctx) {