refactor: improve babashka shebang detection with regex pattern

Replace hardcoded string prefix checks with a flexible regex pattern that matches any absolute path ending in bb or env bb, allows 1-3 spaces between env and bb, supports optional arguments after bb, and prevents false positives from excessive whitespace

Author: Bruce Hauman

src/clojure_mcp/utils/valid_paths.clj

@@ -82,39 +82,38 @@
 
     (validate-path path current-dir allowed-dirs)))
 
-  (defn- babashka-shebang?
-    [file-path]
-    (when (path-exists? file-path)
-      (try
-        (with-open [r (io/reader file-path)]
-          (let [line (-> r line-seq first)]
-            (and line
-                 (or (str/starts-with? line "#!/usr/bin/env bb")
-                     (str/starts-with? line "#!/usr/bin/bb")
-                     (str/starts-with? line "#!/bin/bb")))))
-        (catch Exception _ false))))
-
-  (defn clojure-file?
-    "Checks if a file path has a Clojure-related extension or Babashka shebang."
-
+(defn- babashka-shebang?
+  [file-path]
+  (when (path-exists? file-path)
+    (try
+      (with-open [r (io/reader file-path)]
+        (let [line (-> r line-seq first)]
+          (and line
+               (re-matches #"^#!/[^\s]+/(bb|env\s{1,3}bb)(\s.*)?$" line))))
+      (catch Exception _ false))))
+
+(defn clojure-file?
+  "Checks if a file path has a Clojure-related extension or Babashka shebang.
+   
      Supported extensions:
      - .clj (Clojure)
      - .cljs (ClojureScript)
      - .cljc (Clojure/ClojureScript shared)
      - .bb (Babashka)
      - .edn (Extensible Data Notation)
      - .lpy (Librepl)
+     
      Also detects files starting with a Babashka shebang (`bb`)."
-    [file-path]
-    (when file-path
-      (let [lower-path (str/lower-case file-path)]
-        (or (str/ends-with? lower-path ".clj")
-            (str/ends-with? lower-path ".cljs")
-            (str/ends-with? lower-path ".cljc")
-            (str/ends-with? lower-path ".bb")
-            (str/ends-with? lower-path ".lpy")
-            (str/ends-with? lower-path ".edn")
-            (babashka-shebang? file-path)))))
+  [file-path]
+  (when file-path
+    (let [lower-path (str/lower-case file-path)]
+      (or (str/ends-with? lower-path ".clj")
+          (str/ends-with? lower-path ".cljs")
+          (str/ends-with? lower-path ".cljc")
+          (str/ends-with? lower-path ".bb")
+          (str/ends-with? lower-path ".lpy")
+          (str/ends-with? lower-path ".edn")
+          (babashka-shebang? file-path)))))
 
 (defn extract-paths-from-bash-command
   "Extract file/directory paths from a bash command string.