Add desktop side-by-side layout and fix pitch direction

- Add media query for desktop (900px+): video and controls side by side
- Fix joystick pitch: up now correctly looks up (was inverted)
- Canvas Y increases downward, so up = negative joystickY = negative pitch

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

index.html

@@ -534,6 +534,61 @@
             font-family: monospace;
         }
 
+        /* Desktop Layout - Side by Side */
+        @media (min-width: 900px) {
+            .app-container {
+                display: grid;
+                grid-template-columns: 1fr 1fr;
+                grid-template-rows: auto auto auto auto;
+                max-width: 1200px;
+                gap: 12px;
+            }
+
+            .video-container {
+                grid-column: 1;
+                grid-row: 1 / 3;
+            }
+
+            .state-bar {
+                grid-column: 1;
+                grid-row: 3;
+            }
+
+            #robotSelector {
+                grid-column: 1;
+                grid-row: 4;
+            }
+
+            .panel:nth-of-type(1) { /* Head Control */
+                grid-column: 2;
+                grid-row: 1;
+            }
+
+            .panel:nth-of-type(2) { /* Antennas */
+                grid-column: 2;
+                grid-row: 2;
+            }
+
+            .panel:nth-of-type(3) { /* Sound & Voice */
+                grid-column: 2;
+                grid-row: 3;
+            }
+
+            .panel:nth-of-type(4) { /* Recording */
+                grid-column: 2;
+                grid-row: 4;
+            }
+
+            .joystick-area {
+                width: 220px;
+                height: 220px;
+            }
+
+            .roll-slider {
+                height: 200px;
+            }
+        }
+
         /* Login View */
         .login-view {
             min-height: 100vh;
@@ -1180,10 +1235,10 @@
                 const rollInput = parseFloat(rollSlider.value) / 100;
 
                 // Joystick mapping:
-                // Left/Right (X) controls Yaw: left = positive yaw (turn left)
-                // Up/Down (Y) controls Pitch: up = negative pitch (look up)
-                targetYaw += -joystickX * speed;      // Right = negative = turn right
-                targetPitch += -joystickY * speed;    // Down = positive = look down
+                // Left/Right (X) controls Yaw: right = turn head right (negative yaw)
+                // Up/Down (Y) controls Pitch: up = look up (negative pitch in this coord system)
+                targetYaw += -joystickX * speed;
+                targetPitch += joystickY * speed;     // Fixed: up (neg Y) → neg pitch → look up
                 targetRoll += rollInput * speed;
 
                 // Clamp to limits