feat: integrate poyraz-ui and reactive-switcher for theme management

- Added poyraz-ui preset CSS import to globals.css for styling.
- Created theme-switcher.md documentation for reactive-switcher usage.
- Added usage-guide.md for comprehensive Poyraz UI instructions.
- Updated package.json to include reactive-switcher as a dependency.
- Modified pnpm-lock.yaml to reflect the addition of reactive-switcher.
- Established themes.ts to export Poyraz UI themes for use in the application.

pnpm-lock.yaml

@@ -17,6 +17,9 @@ importers:
       react-dom:
         specifier: 19.2.3
         version: 19.2.3(react@19.2.3)
+      reactive-switcher:
+        specifier: ^1.0.3
+        version: 1.0.3(react-dom@19.2.3(react@19.2.3))(react@19.2.3)
     devDependencies:
       '@tailwindcss/postcss':
         specifier: ^4
@@ -1641,6 +1644,12 @@ packages:
     resolution: {integrity: sha512-Ku/hhYbVjOQnXDZFv2+RibmLFGwFdeeKHFcOTlrt7xplBnya5OGn/hIRDsqDiSUcfORsDC7MPxwork8jBwsIWA==}
     engines: {node: '>=0.10.0'}
 
+  reactive-switcher@1.0.3:
+    resolution: {integrity: sha512-d5kGGUdDZ0z4kdgmBwNOL9Z6qQKYqv6tyifde+6XXbWQZpY5oNbkuA2WNXut6ETwbIbBNa3+dvHWR66XIapqlw==}
+    peerDependencies:
+      react: '>=18.0.0'
+      react-dom: '>=18.0.0'
+
   reflect.getprototypeof@1.0.10:
     resolution: {integrity: sha512-00o4I+DVrefhv+nX0ulyi3biSHCPDe+yLv5o/p6d/UVlirijB8E16FtfwSAi4g3tcqrQ4lRAqQSoFEZJehYEcw==}
     engines: {node: '>= 0.4'}
@@ -3626,6 +3635,11 @@ snapshots:
 
   react@19.2.3: {}
 
+  reactive-switcher@1.0.3(react-dom@19.2.3(react@19.2.3))(react@19.2.3):
+    dependencies:
+      react: 19.2.3
+      react-dom: 19.2.3(react@19.2.3)
+
   reflect.getprototypeof@1.0.10:
     dependencies:
       call-bind: 1.0.8