Refactor UI auth flow, remove uploads app files

Rework client UI state: move and update showLogin/showApp in public/app.js to explicitly set display styles when toggling screens and ensure user info and file load on app show. Remove the theme toggle from public/index.html and simplify CSS by collapsing color variable definitions (dark-theme-focused) in public/style.css. Add a VS Code workspace file. Remove the old uploads/Think app (Dockerfile, package.json, server.js and associated lockfile).

public/index.html

@@ -40,9 +40,7 @@
                 </div>
                 <div class="controls">
                     <span id="user-display"></span>
-                    <button id="theme-toggle" class="btn secondary" aria-label="Toggle Dark Mode">
-                        <span class="icon">🌓</span>
-                    </button>
+
                     <button id="logout-btn" class="btn secondary">Logout</button>
                 </div>
             </header>