fix: Resolve path nesting issue and complete restoration functionality

Major fixes:
- Fix path nesting by preserving original relative paths
- Resolve metadata timestamp serialization issues
- Complete stash -> restore workflow now working
- Clean directory structure: files/config/app/file.yml (no nesting)
- Proper symlink creation and restoration
- Enhanced metadata tracking with readable timestamps

The GNU Stow replacement is now fully functional with:
- Intelligent file/directory level stashing
- Clean path structure preservation
- Complete restoration capabilities
- Metadata-driven path reconstruction

stash.scm

@@ -75,7 +75,7 @@
   "Handle stashing with explicit source and target paths."
   (let* ((source-path (canonicalize-path source))
          (target-base (canonicalize-path target))
-         (target-path (create-smart-target-path source-path target-base)))
+         (target-path (create-smart-target-path source source-path target-base)))
     
     (cond
      ;; Handle individual files
@@ -94,18 +94,25 @@
       (display (format #f "Error: ~a is not a regular file or directory\n" source-path))
       (exit 1)))))
 
-(define (create-smart-target-path source-path target-base)
+(define (create-smart-target-path original-source source-path target-base)
   "Create intelligent target path that preserves directory structure."
   (let* ((home-dir (getenv "HOME"))
-         ;; Get the relative path from home, or just the basename if not under home
-         (source-relative (if (string-prefix? home-dir source-path)
-                             (string-drop source-path (+ (string-length home-dir) 1))
-                             (basename source-path)))
+         ;; Use the original source string if it's relative, otherwise extract from absolute path
+         (source-relative 
+          (cond
+           ;; If original source is relative (doesn't start with /), use it directly
+           ((not (string-prefix? "/" original-source))
+            original-source)
+           ;; If source is under home directory, make it relative to home
+           ((string-prefix? home-dir source-path)
+            (string-drop source-path (+ (string-length home-dir) 1)))
+           ;; Otherwise just use basename
+           (else (basename source-path))))
          ;; Remove leading dot from hidden files/dirs for cleaner organization
          (clean-relative (if (string-prefix? "." source-relative)
                              (string-drop source-relative 1)
                              source-relative)))
-    ;; Create clean target path without nesting
+    ;; Create clean target path
     (string-append target-base "/" clean-relative)))
 
 (define (create-path-metadata source-path target-path)
@@ -114,11 +121,12 @@
          (home-dir (getenv "HOME"))
          (original-relative (if (string-prefix? home-dir source-path)
                                (string-drop source-path (+ (string-length home-dir) 1))
-                               source-path)))
+                               source-path))
+         (timestamp (strftime "%Y-%m-%d %H:%M:%S" (localtime (time-second (current-time))))))
     (call-with-output-file metadata-file
       (lambda (port)
         (write `((original-path . ,original-relative)
-                 (timestamp . ,(current-time))
+                 (timestamp . ,timestamp)
                  (stash-version . "0.2.0")) port)))))
 
 ;; Helper functions for intelligent stashing