testing: text selection, copy/paste, and file drag-drop

[arcaven]

Changes to test

Commit ae8cfff on develop — implements #40.

1. Native text selection in conversation (Shift+mouse)

What changed: Holding Shift while clicking/dragging in the conversation area releases mouse capture so the terminal handles text selection natively. Mouse capture re-enables on the next keypress.

Test objectives:

• Shift+click-drag selects text in the conversation area
• Selected text can be copied via terminal copy (Cmd+C on macOS)
• After copying, pressing any key re-enables mouse capture (scroll wheel works again)
• Normal mouse wheel scroll still works when not in selection mode
• Test in: iTerm2, WezTerm, Kitty (if available)
• Test inside tmux session (Shift+mouse should bypass tmux too)

2. Input text selection (Shift+Arrow)

What changed: Shift+Left/Right/Home/End creates text selections in the input box. Ctrl+C copies selection to clipboard (via OSC 52). Ctrl+X cuts. Typing or backspace replaces selection.

Test objectives:

• Shift+Right selects characters forward
• Shift+Left selects characters backward
• Shift+Home selects from cursor to start
• Shift+End selects from cursor to end
• Ctrl+C with selection copies to clipboard (paste elsewhere to verify)
• Ctrl+C without selection still quits
• Ctrl+X with selection cuts (text removed, available in clipboard)
• Ctrl+X without selection still toggles tool expand
• Typing with active selection replaces it
• Backspace with active selection deletes it
• Arrow keys without Shift clear the selection
• Status bar shows "Copied to clipboard" / "Cut to clipboard"

3. Paste and file drag-drop

What changed: Bracketed paste now preserves newlines. Dragging a file onto the terminal inserts it as @/path/to/file for Claude Code file reference.

Test objectives:

• Paste multiline text — newlines preserved in input
• Paste into existing selection — replaces selection
• Drag-drop a file onto the terminal — inserts as @-mention
• Drag-drop a non-existent path — inserted as plain text (no @ prefix)

OSC 52 clipboard compatibility

• iTerm2: clipboard write works
• WezTerm: clipboard write works
• Kitty: clipboard write works (may need clipboard_control write-clipboard in kitty.conf)
• Inside tmux: clipboard write works (needs set -g set-clipboard on in tmux.conf)

Feedback wanted

• Does Ctrl+C dual behavior (copy with selection, quit without) feel natural?
• Is OSC 52 clipboard working in your terminal? Some terminals require explicit opt-in.
• Does the @-mention insertion for file drop match Claude Code's behavior?

[arcavenai]

Tested in forestage f6cb783 via forestage --persona naomi-nagata --theme the-expanse in wezterm on Wayland.

• ✅ Mouse text selection works
• ✅ Copy / paste (ctrl+shift+c) works
• ❌ Drag-and-drop a file onto the window — no effect

Also surfaced a related distinct concern (mouse scroll wheel hijacked by prompt input history rather than scrolling chat output) — filed separately at #56.