fix(routes): serve pages with clean URLs (no .html extension)

Add server-side routes for /profile, /admin, and /shared that
serve their respective HTML pages directly (same pattern already
used for /login). Updated all frontend references to use clean
URLs instead of .html extensions.

Fixes #99

static/js/app.js

@@ -207,7 +207,7 @@ function setupUserMenu() {
     if (adminBtn) {
         adminBtn.addEventListener('click', () => {
             wrapper.classList.remove('open');
-            window.location.href = '/admin.html';
+            window.location.href = '/admin';
         });
     }
     
@@ -215,7 +215,7 @@ function setupUserMenu() {
     if (profileBtn) {
         profileBtn.addEventListener('click', () => {
             wrapper.classList.remove('open');
-            window.location.href = '/profile.html';
+            window.location.href = '/profile';
         });
     }
     
@@ -1627,7 +1627,7 @@ async function checkAuthentication() {
                 if (!exchangeResponse.ok) {
                     const errText = await exchangeResponse.text();
                     console.error('OIDC token exchange failed:', exchangeResponse.status, errText);
-                    window.location.href = '/login.html?source=oidc_error';
+                    window.location.href = '/login?source=oidc_error';
                     return;
                 }
                 
@@ -1677,7 +1677,7 @@ async function checkAuthentication() {
                 }
             } catch (err) {
                 console.error('OIDC exchange error:', err);
-                window.location.href = '/login.html?source=oidc_error';
+                window.location.href = '/login?source=oidc_error';
                 return;
             }
         }
@@ -1688,7 +1688,7 @@ async function checkAuthentication() {
         if (!token) {
             console.log('No token found, redirecting to login');
             // Avoid potential loop by adding a parameter
-            const redirectUrl = '/login.html?source=app';
+            const redirectUrl = '/login?source=app';
             window.location.href = redirectUrl;
             return;
         }
@@ -1931,7 +1931,7 @@ function logout() {
     sessionStorage.removeItem('redirect_count');
     
     // Redirect to login page with correct path
-    window.location.href = '/login.html';
+    window.location.href = '/login';
 }
 
 /**

static/js/auth.js

@@ -1189,14 +1189,14 @@ function redirectToMainApp() {
                 // Ultimate fallback - clear everything and go to a special error page
                 localStorage.clear();
                 sessionStorage.clear();
-                window.location.href = '/login.html?critical=redirect_error';
+                window.location.href = '/login?critical=redirect_error';
             }
         }, 50);
     } catch (error) {
         console.error('Fatal error in redirectToMainApp:', error);
         // Emergency fallback
         try {
-            window.location.href = '/login.html?error=redirect_fatal';
+            window.location.href = '/login?error=redirect_fatal';
         } catch (e) {
             // Nothing more we can do
             alert('Critical redirect error. Please reload the page and try again.');
@@ -1215,5 +1215,5 @@ function logout() {
     localStorage.removeItem(REFRESH_TOKEN_KEY);
     localStorage.removeItem(TOKEN_EXPIRY_KEY);
     localStorage.removeItem(USER_DATA_KEY);
-    window.location.href = '/login.html';
+    window.location.href = '/login';
 }

static/js/shared.js

@@ -15,7 +15,7 @@ function checkAuthentication() {
     
     if (!token || !tokenExpiry || new Date(tokenExpiry) < new Date()) {
         // No token or expired token
-        window.location.href = '/login.html';
+        window.location.href = '/login';
         return;
     }