feat(v0.3): M3 themes/font settings + M7 session dashboard

- M3: settings.ts (⚙ panel: dark/light/solarized theme + font size A-/A+),
  persisted to localStorage; terminal-session.applyTheme; TabApp.applySettings
  applies to all + new tabs
- M7: dashboard.ts (▦ overlay listing every tab with connection dot + folder +
  Claude status; click a row to focus; live re-render while open);
  TabApp.snapshot()/focusTab()
- Browser-verified: light theme renders + persists; dashboard lists tabs and
  focuses on click. 208 tests green, typechecks + build ok.

public/settings.ts

@@ -0,0 +1,128 @@
+/**
+ * public/settings.ts — theme + font-size settings (M3).
+ *
+ * A ⚙ toolbar button opens a small panel; choices persist to localStorage and
+ * apply to every terminal via the onChange callback.
+ */
+
+import type { ITheme } from '@xterm/xterm'
+
+export interface Settings {
+  theme: string
+  fontSize: number
+}
+
+export const THEMES: Record<string, ITheme> = {
+  dark: { background: '#1a1a1a', foreground: '#e8e8e8', cursor: '#e8e8e8' },
+  light: {
+    background: '#f5f5f5',
+    foreground: '#1a1a1a',
+    cursor: '#1a1a1a',
+    selectionBackground: '#bcd3f5',
+  },
+  solarized: { background: '#002b36', foreground: '#93a1a1', cursor: '#93a1a1' },
+}
+
+const KEY = 'web-terminal:settings'
+export const DEFAULT_SETTINGS: Settings = { theme: 'dark', fontSize: 14 }
+
+export function loadSettings(): Settings {
+  try {
+    const raw = localStorage.getItem(KEY)
+    if (raw) {
+      const s = JSON.parse(raw) as Partial<Settings>
+      return {
+        theme: typeof s.theme === 'string' && THEMES[s.theme] ? s.theme : DEFAULT_SETTINGS.theme,
+        fontSize:
+          typeof s.fontSize === 'number' && s.fontSize >= 10 && s.fontSize <= 24
+            ? s.fontSize
+            : DEFAULT_SETTINGS.fontSize,
+      }
+    }
+  } catch {
+    // ignore
+  }
+  return { ...DEFAULT_SETTINGS }
+}
+
+function saveSettings(s: Settings): void {
+  try {
+    localStorage.setItem(KEY, JSON.stringify(s))
+  } catch {
+    // ignore
+  }
+}
+
+export function mountSettings(
+  toolbar: HTMLElement,
+  current: () => Settings,
+  onChange: (s: Settings) => void,
+): void {
+  const panel = document.createElement('div')
+  panel.id = 'settingspanel'
+  panel.style.display = 'none'
+
+  const apply = (next: Settings): void => {
+    saveSettings(next)
+    onChange(next)
+    render()
+  }
+
+  function render(): void {
+    const s = current()
+    panel.replaceChildren()
+
+    const themeRow = document.createElement('div')
+    themeRow.className = 'settings-row'
+    themeRow.append(label('Theme'))
+    for (const key of Object.keys(THEMES)) {
+      const b = document.createElement('button')
+      b.textContent = key
+      b.className = key === s.theme ? 'settings-opt active' : 'settings-opt'
+      b.addEventListener('click', () => apply({ ...s, theme: key }))
+      themeRow.appendChild(b)
+    }
+
+    const fontRow = document.createElement('div')
+    fontRow.className = 'settings-row'
+    fontRow.append(label('Font'))
+    const minus = document.createElement('button')
+    minus.className = 'settings-opt'
+    minus.textContent = 'A−'
+    minus.addEventListener('click', () => apply({ ...s, fontSize: Math.max(10, s.fontSize - 1) }))
+    const size = document.createElement('span')
+    size.className = 'settings-size'
+    size.textContent = String(s.fontSize)
+    const plus = document.createElement('button')
+    plus.className = 'settings-opt'
+    plus.textContent = 'A+'
+    plus.addEventListener('click', () => apply({ ...s, fontSize: Math.min(24, s.fontSize + 1) }))
+    fontRow.append(minus, size, plus)
+
+    panel.append(themeRow, fontRow)
+  }
+
+  function label(text: string): HTMLElement {
+    const el = document.createElement('span')
+    el.className = 'settings-label'
+    el.textContent = text
+    return el
+  }
+
+  document.body.appendChild(panel)
+
+  const toggle = document.createElement('button')
+  toggle.className = 'toolbtn'
+  toggle.textContent = '⚙'
+  toggle.title = 'Settings (theme, font)'
+  toggle.setAttribute('aria-label', 'Settings')
+  toggle.addEventListener('click', () => {
+    if (panel.style.display === 'none') {
+      render()
+      panel.style.display = 'block'
+    } else {
+      panel.style.display = 'none'
+    }
+  })
+  toolbar.appendChild(toggle)
+}