feat(ui): add terminal theme picker with ANSI color swatches

ThemePicker modal shows all 7 built-in themes with 16-color ANSI
previews and a live prompt sample. StatusBar theme name is now
clickable to open the picker. Active theme is visually highlighted.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/components/common/StatusBar.vue

@@ -20,7 +20,13 @@
 
     <!-- Right: terminal info -->
     <div class="flex items-center gap-3">
-      <span>Theme: Dracula</span>
+      <button
+        class="hover:text-[var(--wraith-text-primary)] transition-colors cursor-pointer"
+        title="Change terminal theme"
+        @click="emit('open-theme-picker')"
+      >
+        Theme: {{ activeThemeName }}
+      </button>
       <span>UTF-8</span>
       <span>120&times;40</span>
     </div>
@@ -28,13 +34,19 @@
 </template>
 
 <script setup lang="ts">
-import { computed } from "vue";
+import { computed, ref } from "vue";
 import { useSessionStore } from "@/stores/session.store";
 import { useConnectionStore } from "@/stores/connection.store";
 
 const sessionStore = useSessionStore();
 const connectionStore = useConnectionStore();
 
+const activeThemeName = ref("Dracula");
+
+const emit = defineEmits<{
+  (e: "open-theme-picker"): void;
+}>();
+
 const connectionInfo = computed(() => {
   const session = sessionStore.activeSession;
   if (!session) return "";
@@ -44,4 +56,10 @@ const connectionInfo = computed(() => {
 
   return `root@${conn.hostname}:${conn.port}`;
 });
+
+function setThemeName(name: string): void {
+  activeThemeName.value = name;
+}
+
+defineExpose({ setThemeName, activeThemeName });
 </script>

frontend/src/components/common/ThemePicker.vue

@@ -0,0 +1,200 @@
+<template>
+  <Teleport to="body">
+    <div
+      v-if="visible"
+      class="fixed inset-0 z-50 flex items-center justify-center"
+      @click.self="close"
+      @keydown.esc="close"
+    >
+      <!-- Backdrop -->
+      <div class="absolute inset-0 bg-black/50" @click="close" />
+
+      <!-- Picker panel -->
+      <div class="relative w-full max-w-md bg-[#161b22] border border-[#30363d] rounded-lg shadow-2xl overflow-hidden">
+        <!-- Header -->
+        <div class="flex items-center justify-between px-4 py-3 border-b border-[#30363d]">
+          <h3 class="text-sm font-semibold text-[var(--wraith-text-primary)]">Terminal Theme</h3>
+          <button
+            class="text-[var(--wraith-text-muted)] hover:text-[var(--wraith-text-primary)] transition-colors cursor-pointer"
+            @click="close"
+          >
+            <svg class="w-4 h-4" viewBox="0 0 16 16" fill="currentColor">
+              <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 1 1 1.06 1.06L9.06 8l3.22 3.22a.749.749 0 1 1-1.06 1.06L8 9.06l-3.22 3.22a.749.749 0 1 1-1.06-1.06L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z" />
+            </svg>
+          </button>
+        </div>
+
+        <!-- Theme list -->
+        <div class="max-h-96 overflow-y-auto py-2">
+          <button
+            v-for="theme in themes"
+            :key="theme.name"
+            class="w-full flex items-center gap-3 px-4 py-2.5 text-left transition-colors cursor-pointer"
+            :class="activeTheme === theme.name ? 'bg-[#1f6feb]/20' : 'hover:bg-[#30363d]'"
+            @click="selectTheme(theme)"
+          >
+            <!-- Active indicator -->
+            <span class="w-4 flex items-center justify-center shrink-0">
+              <svg
+                v-if="activeTheme === theme.name"
+                class="w-4 h-4 text-[#3fb950]"
+                viewBox="0 0 16 16"
+                fill="currentColor"
+              >
+                <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z" />
+              </svg>
+            </span>
+
+            <!-- Theme info -->
+            <div class="flex-1 min-w-0">
+              <div class="text-sm text-[var(--wraith-text-primary)]">{{ theme.name }}</div>
+              <!-- Color swatch: 16 ANSI colors as small blocks -->
+              <div class="flex gap-0.5 mt-1.5">
+                <span
+                  v-for="(color, i) in themeColors(theme)"
+                  :key="i"
+                  class="w-4 h-3 rounded-sm"
+                  :style="{ backgroundColor: color }"
+                />
+              </div>
+            </div>
+
+            <!-- Preview: fg on bg -->
+            <div
+              class="px-2 py-1 rounded text-[10px] font-mono shrink-0"
+              :style="{ backgroundColor: theme.background, color: theme.foreground }"
+            >
+              ~/wraith $
+            </div>
+          </button>
+        </div>
+      </div>
+    </div>
+  </Teleport>
+</template>
+
+<script setup lang="ts">
+import { ref } from "vue";
+
+export interface ThemeDefinition {
+  name: string;
+  foreground: string;
+  background: string;
+  cursor: string;
+  black: string;
+  red: string;
+  green: string;
+  yellow: string;
+  blue: string;
+  magenta: string;
+  cyan: string;
+  white: string;
+  brightBlack: string;
+  brightRed: string;
+  brightGreen: string;
+  brightYellow: string;
+  brightBlue: string;
+  brightMagenta: string;
+  brightCyan: string;
+  brightWhite: string;
+}
+
+const visible = ref(false);
+const activeTheme = ref("Dracula");
+
+// Built-in themes matching the Go theme.BuiltinThemes
+const themes: ThemeDefinition[] = [
+  {
+    name: "Dracula",
+    foreground: "#f8f8f2", background: "#282a36", cursor: "#f8f8f2",
+    black: "#21222c", red: "#ff5555", green: "#50fa7b", yellow: "#f1fa8c",
+    blue: "#bd93f9", magenta: "#ff79c6", cyan: "#8be9fd", white: "#f8f8f2",
+    brightBlack: "#6272a4", brightRed: "#ff6e6e", brightGreen: "#69ff94",
+    brightYellow: "#ffffa5", brightBlue: "#d6acff", brightMagenta: "#ff92df",
+    brightCyan: "#a4ffff", brightWhite: "#ffffff",
+  },
+  {
+    name: "Nord",
+    foreground: "#d8dee9", background: "#2e3440", cursor: "#d8dee9",
+    black: "#3b4252", red: "#bf616a", green: "#a3be8c", yellow: "#ebcb8b",
+    blue: "#81a1c1", magenta: "#b48ead", cyan: "#88c0d0", white: "#e5e9f0",
+    brightBlack: "#4c566a", brightRed: "#bf616a", brightGreen: "#a3be8c",
+    brightYellow: "#ebcb8b", brightBlue: "#81a1c1", brightMagenta: "#b48ead",
+    brightCyan: "#8fbcbb", brightWhite: "#eceff4",
+  },
+  {
+    name: "Monokai",
+    foreground: "#f8f8f2", background: "#272822", cursor: "#f8f8f0",
+    black: "#272822", red: "#f92672", green: "#a6e22e", yellow: "#f4bf75",
+    blue: "#66d9ef", magenta: "#ae81ff", cyan: "#a1efe4", white: "#f8f8f2",
+    brightBlack: "#75715e", brightRed: "#f92672", brightGreen: "#a6e22e",
+    brightYellow: "#f4bf75", brightBlue: "#66d9ef", brightMagenta: "#ae81ff",
+    brightCyan: "#a1efe4", brightWhite: "#f9f8f5",
+  },
+  {
+    name: "One Dark",
+    foreground: "#abb2bf", background: "#282c34", cursor: "#528bff",
+    black: "#282c34", red: "#e06c75", green: "#98c379", yellow: "#e5c07b",
+    blue: "#61afef", magenta: "#c678dd", cyan: "#56b6c2", white: "#abb2bf",
+    brightBlack: "#545862", brightRed: "#e06c75", brightGreen: "#98c379",
+    brightYellow: "#e5c07b", brightBlue: "#61afef", brightMagenta: "#c678dd",
+    brightCyan: "#56b6c2", brightWhite: "#c8ccd4",
+  },
+  {
+    name: "Solarized Dark",
+    foreground: "#839496", background: "#002b36", cursor: "#839496",
+    black: "#073642", red: "#dc322f", green: "#859900", yellow: "#b58900",
+    blue: "#268bd2", magenta: "#d33682", cyan: "#2aa198", white: "#eee8d5",
+    brightBlack: "#002b36", brightRed: "#cb4b16", brightGreen: "#586e75",
+    brightYellow: "#657b83", brightBlue: "#839496", brightMagenta: "#6c71c4",
+    brightCyan: "#93a1a1", brightWhite: "#fdf6e3",
+  },
+  {
+    name: "Gruvbox Dark",
+    foreground: "#ebdbb2", background: "#282828", cursor: "#ebdbb2",
+    black: "#282828", red: "#cc241d", green: "#98971a", yellow: "#d79921",
+    blue: "#458588", magenta: "#b16286", cyan: "#689d6a", white: "#a89984",
+    brightBlack: "#928374", brightRed: "#fb4934", brightGreen: "#b8bb26",
+    brightYellow: "#fabd2f", brightBlue: "#83a598", brightMagenta: "#d3869b",
+    brightCyan: "#8ec07c", brightWhite: "#ebdbb2",
+  },
+  {
+    name: "MobaXTerm Classic",
+    foreground: "#ececec", background: "#242424", cursor: "#b4b4c0",
+    black: "#000000", red: "#aa4244", green: "#7e8d53", yellow: "#e4b46d",
+    blue: "#6e9aba", magenta: "#9e5085", cyan: "#80d5cf", white: "#cccccc",
+    brightBlack: "#808080", brightRed: "#cc7b7d", brightGreen: "#a5b17c",
+    brightYellow: "#ecc995", brightBlue: "#96b6cd", brightMagenta: "#c083ac",
+    brightCyan: "#a9e2de", brightWhite: "#cccccc",
+  },
+];
+
+function themeColors(theme: ThemeDefinition): string[] {
+  return [
+    theme.black, theme.red, theme.green, theme.yellow,
+    theme.blue, theme.magenta, theme.cyan, theme.white,
+    theme.brightBlack, theme.brightRed, theme.brightGreen, theme.brightYellow,
+    theme.brightBlue, theme.brightMagenta, theme.brightCyan, theme.brightWhite,
+  ];
+}
+
+const emit = defineEmits<{
+  (e: "select", theme: ThemeDefinition): void;
+}>();
+
+function selectTheme(theme: ThemeDefinition): void {
+  activeTheme.value = theme.name;
+  emit("select", theme);
+  // TODO: Apply theme to xterm.js via Wails binding — ThemeService.SetActive(theme.name)
+}
+
+function open(): void {
+  visible.value = true;
+}
+
+function close(): void {
+  visible.value = false;
+}
+
+defineExpose({ open, close, visible, activeTheme });
+</script>