Add comprehensive PRD and terminal UX improvements

- Add PRD.md with detailed product requirements documentation
- Unify tmux screen size presets to consistent 24-row height
- Add Ctrl+Down keyboard shortcut to scroll terminal to bottom

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

client/src/lib/components/TerminalView.svelte

@@ -198,6 +198,13 @@
 	}
 
 	async function handleKeydown(event: KeyboardEvent) {
+		// Ctrl+Down scrolls to bottom (don't send to tmux)
+		if (event.ctrlKey && event.key === 'ArrowDown') {
+			event.preventDefault();
+			scrollToBottom();
+			return;
+		}
+
 		if (!isAlive) return;
 
 		// Prevent default for all keys we handle
@@ -450,7 +457,7 @@
 				class="px-1 py-0.5 rounded-sm text-[10px] font-mono transition-colors {screenMode === 'portrait' ? 'bg-cyan-600 text-white' : 'bg-zinc-700 hover:bg-zinc-600 text-zinc-200'} disabled:opacity-50"
 				title="Portrait (50x60)"
 			>
-				<svg xmlns="http://www.w3.org/2000/svg" class="h-3 w-2.5 inline-block" fill="none" viewBox="0 0 10 16" stroke="currentColor" stroke-width="1.5">
+				<svg xmlns="http://www.w3.org/2000/svg" class="h-2.5 w-2 inline-block" fill="none" viewBox="0 0 10 16" stroke="currentColor" stroke-width="1.5">
 					<rect x="1" y="1" width="8" height="14" rx="1" />
 				</svg>
 			</button>
@@ -470,7 +477,7 @@
 				class="px-1 py-0.5 rounded-sm text-[10px] font-mono transition-colors {screenMode === 'desktop' ? 'bg-cyan-600 text-white' : 'bg-zinc-700 hover:bg-zinc-600 text-zinc-200'} disabled:opacity-50"
 				title="Split screen (100x40)"
 			>
-				<svg xmlns="http://www.w3.org/2000/svg" class="h-3 w-3.5 inline-block" fill="none" viewBox="0 0 20 14" stroke="currentColor" stroke-width="1.5">
+				<svg xmlns="http://www.w3.org/2000/svg" class="h-2.5 w-3.5 inline-block" fill="none" viewBox="0 0 20 14" stroke="currentColor" stroke-width="1.5">
 					<rect x="1" y="1" width="8" height="12" rx="1" />
 					<rect x="11" y="1" width="8" height="12" rx="1" />
 				</svg>
@@ -481,7 +488,7 @@
 				class="px-1 py-0.5 rounded-sm text-[10px] font-mono transition-colors {screenMode === 'fullscreen' ? 'bg-cyan-600 text-white' : 'bg-zinc-700 hover:bg-zinc-600 text-zinc-200'} disabled:opacity-50"
 				title="Fullscreen (180x60)"
 			>
-				<svg xmlns="http://www.w3.org/2000/svg" class="h-3 w-4 inline-block" fill="none" viewBox="0 0 22 14" stroke="currentColor" stroke-width="1.5">
+				<svg xmlns="http://www.w3.org/2000/svg" class="h-2.5 w-4 inline-block" fill="none" viewBox="0 0 22 14" stroke="currentColor" stroke-width="1.5">
 					<rect x="1" y="1" width="20" height="12" rx="1" />
 				</svg>
 			</button>

server/src/spiceflow/adapters/tmux.clj

@@ -339,10 +339,10 @@
 
 ;; Screen size presets for different device orientations
 (def ^:private screen-sizes
-  {:fullscreen {:width 180 :height 60}
+  {:fullscreen {:width 180 :height 24}
-   :desktop    {:width 100 :height 40}
+   :desktop    {:width 100 :height 24}
    :landscape  {:width 65  :height 24}
-   :portrait   {:width 40  :height 35}})
+   :portrait   {:width 40  :height 24}})
 
 (defn resize-session
   "Resize a tmux session window to a preset size.