game kit gear menu + login form UX polish; left-side position indicator flip

game kit: new Applet model rows (context=game-kit) for Trinkets, Tokens, Card Decks, Dice Sets via applets migration 0008; _game_kit_context() helper in gameboard.views; toggle_game_kit_sections view + URL; new _game_kit_sections.html (HTMX-swappable, visibility-conditional) + _game_kit_applet_menu.html partials; game_kit.html wired to gear btn + menu; Dice Sets now renders _forthcoming.html partial; 16 new green ITs in GameKitViewTest + ToggleGameKitSectionsViewTest

login form: .input-group now position:fixed + vertically centred (top:50%) across all breakpoints as default; landscape block reduced to left/right sidebar offsets only; form-control width 24rem, text-align:center; alert block moved below h2 in base.html; alert margin 0.75rem all sides; home.html header switches between Howdy Stranger (anon) and Dashboard (authed)

room.html position indicators: slots 3/4/5 (AC/SC/EC) column order flipped via SCSS data-slot selectors so .fa-chair sits table-side and label+status icon sit outward

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/static_src/scss/_base.scss

@@ -68,13 +68,20 @@ body {
         }
 
         .input-group {
+            position: fixed;
+            left: 0;
+            right: 0;
+            top: 50%;
+            transform: translateY(-50%);
             display: flex;
             flex-direction: column;
             align-items: center;
             gap: 0.5rem;
+            z-index: 50;
 
             .form-control {
-                width: auto;
+                width: 24rem;
+                text-align: center;
             }
         }
 
@@ -117,7 +124,7 @@ body {
 
         .alert {
             padding: 0.75rem 1rem;
-            margin: 0.75rem 0;
+            margin: 0.75rem;
             border-radius: 0.5rem;
             border: 0.1rem solid rgba(var(--priYl), 0.5);
             color: rgba(var(--priYl), 1);
@@ -243,17 +250,10 @@ body {
             // margin-left: 0.75rem;
         }
 
-        // Login form: pull out of narrow sidebar, centre in the viewport content area
+        // Login form: offset from fixed sidebars in landscape
         .input-group {
-            display: flex;
-            position: fixed;
             left: $sidebar-w;
             right: $sidebar-w;
-            top: 50%;
-            transform: translateY(-50%);
-            flex-direction: column;
-            align-items: center;
-            z-index: 50;
 
             .navbar-text {
                 writing-mode: horizontal-tb;