feat(demo): make video player fill content area, compact resources strip

- .video-area: flex: 1 so it fills remaining height instead of shrinking
- #ingest: height: 100%, removed max-height cap
- .resources-pane: fixed 160px height at bottom, tighter padding
- .section-header: margin-bottom 12px → 8px to fit compact pane

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

Author: LucasMaupin

packages/demo/src/index.html

@@ -329,14 +329,16 @@
       .video-area {
         position: relative;
         background: #000;
-        flex-shrink: 0;
+        flex: 1;
+        min-height: 0;
         border-bottom: 1px solid var(--border);
+        overflow: hidden;
       }
 
       #ingest {
         display: block;
         width: 100%;
-        max-height: 400px;
+        height: 100%;
         object-fit: contain;
         background: #000;
       }
@@ -365,16 +367,17 @@
       /* ── Resources pane ──────────────────────────────── */
 
       .resources-pane {
-        flex: 1;
+        flex-shrink: 0;
+        height: 160px;
         overflow-y: auto;
-        padding: 16px;
+        padding: 10px 16px;
       }
 
       .section-header {
         display: flex;
         align-items: center;
         justify-content: space-between;
-        margin-bottom: 12px;
+        margin-bottom: 8px;
       }
 
       .section-title {