Add import/export to README, research scope guidance to CLAUDE.md

Add import/export feature bullet to README.md (constitution requires
README updates when user-facing capabilities change). Add research
scope note to CLAUDE.md RPI section: research phases should scan for
existing patterns and consolidation opportunities, not just what the
feature needs. Remove auto-generated Active Technologies / Recent
Changes sections that duplicated Tech Stack.

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

README.md

@@ -9,6 +9,7 @@ A local-first initiative tracker and encounter manager for tabletop RPGs (D&D 5e
 - **Bestiary integration** — import bestiary JSON sources, search creatures, and view full stat blocks
 - **Player characters** — create reusable player character templates with name, AC, HP, color, and icon; search and add them to encounters with pre-filled stats; manage (edit/delete) from a dedicated panel
 - **Undo/redo** — reverse any encounter action with Undo/Redo buttons or keyboard shortcuts (Ctrl+Z / Ctrl+Shift+Z, Cmd on Mac); history persists across page reloads
+- **Import/export** — export the full encounter state (combatants, undo/redo history, player characters) as a JSON file or copy to clipboard; import from file upload or pasted JSON with validation and confirmation
 - **Persistent** — encounters survive page reloads via localStorage; bestiary data cached in IndexedDB; player characters stored independently
 
 ## Prerequisites