feat: make team section a floating sidebar on desktop

Add responsive 2-column layout for the encounters page:
- Desktop (lg, ≥1024px): Encounters on left, team in sticky right sidebar
- Mobile/tablet: Keep current stacked layout

The sidebar scrolls independently when team exceeds viewport height.

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

frontend/src/pages/RunEncounters.tsx

@@ -922,7 +922,7 @@ export function RunEncounters() {
   })
 
   return (
-    <div className="max-w-4xl mx-auto p-8">
+    <div className="max-w-4xl lg:max-w-6xl mx-auto p-8">
       {/* Header */}
       <div className="mb-6">
         <Link
@@ -1246,9 +1246,12 @@ export function RunEncounters() {
       {/* Encounters Tab */}
       {activeTab === 'encounters' && (
         <>
-          {/* Team Section */}
+        <div className="lg:flex lg:gap-6">
+          {/* Main content column */}
+          <div className="flex-1 min-w-0">
+          {/* Team Section - Mobile/Tablet only */}
           {(alive.length > 0 || dead.length > 0) && (
-            <div className="mb-6">
+            <div className="mb-6 lg:hidden">
               <div className="flex items-center justify-between mb-3">
                 <button
                   type="button"
@@ -1690,6 +1693,68 @@ export function RunEncounters() {
               )
             })}
           </div>
+          </div>
+
+          {/* Team Sidebar - Desktop only */}
+          {(alive.length > 0 || dead.length > 0) && (
+            <div className="hidden lg:block w-64 shrink-0">
+              <div className="sticky top-20 max-h-[calc(100vh-6rem)] overflow-y-auto">
+                <div className="bg-surface-1 border border-border-default rounded-lg p-4">
+                  <div className="flex items-center justify-between mb-3">
+                    <h2 className="text-lg font-semibold text-text-primary">
+                      {isActive ? 'Team' : 'Final Team'}
+                    </h2>
+                    <span className="text-xs text-text-muted">
+                      {alive.length}/{alive.length + dead.length}
+                    </span>
+                  </div>
+                  {alive.length > 1 && (
+                    <select
+                      value={teamSort}
+                      onChange={(e) => setTeamSort(e.target.value as TeamSortKey)}
+                      className="w-full text-sm border border-border-default rounded-lg px-3 py-1.5 bg-surface-0 text-text-primary mb-3"
+                    >
+                      <option value="route">Route Order</option>
+                      <option value="level">Catch Level</option>
+                      <option value="species">Species Name</option>
+                      <option value="dex">National Dex</option>
+                    </select>
+                  )}
+                  {alive.length > 0 && (
+                    <div className="grid grid-cols-2 gap-2 mb-3">
+                      {alive.map((enc) => (
+                        <PokemonCard
+                          key={enc.id}
+                          encounter={enc}
+                          onClick={
+                            isActive && canEdit ? () => setSelectedTeamEncounter(enc) : undefined
+                          }
+                        />
+                      ))}
+                    </div>
+                  )}
+                  {dead.length > 0 && (
+                    <>
+                      <h3 className="text-sm font-medium text-text-tertiary mb-2">Graveyard</h3>
+                      <div className="grid grid-cols-2 gap-2">
+                        {dead.map((enc) => (
+                          <PokemonCard
+                            key={enc.id}
+                            encounter={enc}
+                            showFaintLevel
+                            onClick={
+                              isActive && canEdit ? () => setSelectedTeamEncounter(enc) : undefined
+                            }
+                          />
+                        ))}
+                      </div>
+                    </>
+                  )}
+                </div>
+              </div>
+            </div>
+          )}
+        </div>
 
           {/* Encounter Modal */}
           {selectedRoute && (