Slopgotchi pet widget added to context inspector

Slopgotchi pet widget added to context inspector

Summary

Added a decorative ASCII pet widget to the context inspector panel. Clicking the pet shows a red heart and cycles through ASCII art frames with a bounce animation.

Changes

• src/tunacode/ui/slopgotchi/ — New module (renamed from tamagochi/)
  • __init__.py — Exports SlopgotchiHandler, SlopgotchiPanelState
  • panel.py — Click handler, ASCII frame cycling, heart animation, margin bounce
• src/tunacode/ui/app.py — Compose includes #field-pet, on_click walks parent tree to detect pet clicks, _touch_slopgotchi and _refresh_slopgotchi methods
• src/tunacode/ui/context_panel.py — Updated imports from slopgotchi module
• src/tunacode/ui/styles/layout.tcss — #field-pet styling
• tests/unit/ui/test_context_panel_summary.py — Pet widget assertions

Key Lessons

• Textual click detection: Do NOT use on_mouse_down with event.control is widget for Static widgets. Use on_click and walk event.widget.parent tree checking IDs.
• Rich Text in Static: Never apply a single style to entire Text(art, style=...) — it colors whitespace too. Build with .append() per segment instead.