feat(ags-v3): brain HUD terminal — kitty toggle + single instance + COSMIC window rule

- BrainPower panel: dashboard only (VTE embed pas compatible AGS JSX)
- toggle-brain.sh: ouvre/ferme panel AGS + terminal Kitty (single instance via pgrep)
- Kitty class brain-hud-terminal pour COSMIC window rule (floating)
- app.ts: cleanup focusBrainTerm removed
- style.scss: brain-terminal class + brain-commits-list

ags-v3/toggle-brain.sh

@@ -1,3 +1,32 @@
 #!/bin/bash
-# Toggle Brain Power panel via AGS IPC
-ags request "toggle-brain" 2>/dev/null
+# Toggle Brain Power — dashboard AGS + terminal Kitty (single instance)
+BRAIN_ROOT="${BRAIN_ROOT:-$HOME/Dev/Brain}"
+KITTY_CLASS="brain-hud-terminal"
+
+# Check if brain kitty is already running (by window class)
+kitty_pid=$(pgrep -f "class $KITTY_CLASS" | head -1)
+
+if [ -n "$kitty_pid" ]; then
+  # Close everything
+  ags request "toggle-brain" 2>/dev/null
+  kill "$kitty_pid" 2>/dev/null
+else
+  # Open everything
+  ags request "toggle-brain" 2>/dev/null
+  kitty \
+    --class "$KITTY_CLASS" \
+    --title "🧠 Brain HUD" \
+    --override remember_window_size=no \
+    --override initial_window_width=60c \
+    --override initial_window_height=30c \
+    --override background_opacity=0.94 \
+    --override background=#1a0e27 \
+    --override foreground=#f0eaf8 \
+    --override cursor=#ff4da6 \
+    --override font_size=13 \
+    --override confirm_os_window_close=0 \
+    --directory "$BRAIN_ROOT" \
+    -e zsh -c "echo '🧠 Brain HUD — navigate mode'; echo ''; exec zsh" \
+    &
+  disown
+fi