Make flake self-contained - consolidate installer-replication

BREAKING CHANGE: Remove external dots-hyprland dependency

- Imported all essential configs from dots-hyprland/installer-replication
- Added complete configs/ directory with:
  - hypr/ - Hyprland configuration
  - quickshell/ - Quickshell widgets and config
  - applications/ - Application configurations
  - scripts/ - Utility scripts
  - matugen/ - Material You theming
- Updated flake.nix to use local ./configs instead of external repo
- Simplified update-flake script (removed external repo management)
- Updated README to reflect self-contained architecture
- All builds pass with local configurations

Benefits:
- No external repository dependencies
- Faster builds (no network dependencies)
- Version controlled configs in single repo
- Easier maintenance and development
- Complete installer replication in one place

configs/quickshell/modules/common/functions/FileUtils.qml

@@ -0,0 +1,41 @@
+pragma Singleton
+import Quickshell
+
+Singleton {
+    id: root
+
+    /**
+     * Trims the File protocol off the input string
+     * @param {string} str
+     * @returns {string}
+     */
+    function trimFileProtocol(str) {
+        return str.startsWith("file://") ? str.slice(7) : str;
+    }
+
+    /**
+     * Extracts the file name from a file path
+     * @param {string} str
+     * @returns {string}
+     */
+    function fileNameForPath(str) {
+        if (typeof str !== "string") return "";
+        const trimmed = trimFileProtocol(str);
+        return trimmed.split(/[\\/]/).pop();
+    }
+
+    /**
+     * Removes the file extension from a file path or name
+     * @param {string} str
+     * @returns {string}
+     */
+    function trimFileExt(str) {
+        if (typeof str !== "string") return "";
+        const trimmed = trimFileProtocol(str);
+        const lastDot = trimmed.lastIndexOf(".");
+        if (lastDot > -1 && lastDot > trimmed.lastIndexOf("/")) {
+            return trimmed.slice(0, lastDot);
+        }
+        return trimmed;
+    }
+}