feat: resizable character panel and full-height sprite

- Change sprite to use full height instead of full width for better scaling
- Add draggable divider between character panel and terminal
- Persist panel width preference in config (min: 200px, max: 600px)

Closes #10

src/lib/components/AnimeGirl.svelte

@@ -57,30 +57,34 @@
   }
 </script>
 
-<div class="anime-girl-container flex flex-col items-center justify-end h-full p-4">
-  <div class="character-frame relative {getBackgroundGlow()} w-full max-w-md">
-    <div class="sprite-container {getAnimationClass()}">
+<div
+  class="anime-girl-container flex flex-col items-center justify-between h-full p-4 overflow-hidden"
+>
+  <div
+    class="character-frame relative {getBackgroundGlow()} flex-1 flex items-center justify-center min-h-0"
+  >
+    <div class="sprite-container {getAnimationClass()} h-full flex items-center justify-center">
       <img
         src="/sprites/{info.spriteFile}"
         alt="Hikari - {info.label}"
-        class="character-sprite w-full h-auto object-contain"
+        class="character-sprite h-full w-auto max-w-full object-contain"
         onerror={(e) => {
           const target = e.currentTarget as HTMLImageElement;
           target.src = "/sprites/placeholder.svg";
         }}
       />
     </div>
+  </div>
 
-    <div class="state-indicator absolute -bottom-2 left-1/2 transform -translate-x-1/2">
-      <div
-        class="px-3 py-1 rounded-full text-xs font-medium bg-[var(--bg-secondary)] border border-[var(--border-color)] text-[var(--accent-primary)]"
-      >
-        {info.label}
-      </div>
+  <div class="state-indicator mt-2">
+    <div
+      class="px-3 py-1 rounded-full text-xs font-medium bg-[var(--bg-secondary)] border border-[var(--border-color)] text-[var(--accent-primary)]"
+    >
+      {info.label}
     </div>
   </div>
 
-  <div class="speech-bubble mt-4 max-w-xs">
+  <div class="speech-bubble mt-2 max-w-xs flex-shrink-0">
     <div
       class="relative bg-[var(--bg-secondary)] rounded-lg px-4 py-2 border border-[var(--border-color)]"
     >

src/lib/components/ConfigSidebar.svelte

@@ -16,6 +16,7 @@
     notification_volume: 0.7,
     always_on_top: false,
     update_checks_enabled: true,
+    character_panel_width: null,
   });
 
   let isOpen = $state(false);

src/lib/components/StatusBar.svelte

@@ -47,6 +47,7 @@
     notification_volume: 0.5,
     always_on_top: false,
     update_checks_enabled: true,
+    character_panel_width: null,
   });
 
   onMount(async () => {