v0.2.0

What's New

• Floating selection toolbar（划词悬浮条）: selecting text inside the conversation flow pops up a small toolbar anchored at the pointer release point, with three actions:
  • 复制 (Copy) — copies the selection to the clipboard with a confirmation flash
  • 朗读 (Read aloud) — speaks the selection via the browser's speechSynthesis, toggling to stop
  • 提问 (Ask) — inserts the selection into the composer as a Markdown quote block, caret ready on the next line
• Toolbar follows the live selection rect while scrolling; Escape / outside click dismisses; toolbar clicks never re-anchor it.