feat: Update Notepad to use Metadata (READ ME)

- Potential breaking changes; SAVE your notes before updating
- The new system will store files locally to free up Session data
- Session metadata will be saved in JSON via: `notepad-session.json`
- Local files will be saved in: `/.local/state/DankMaterialShell/notepad-files`

.gitignore

@@ -63,6 +63,11 @@ CLAUDE-temp.md
 niri-colors.generated.kdl
 ghostty-colors.generated.conf
 
+# Notepad files (should be in ~/.local/state/DankMaterialShell/)
+untitled-*.txt
+file:*
+notepad-files/
+
 result
 
 # If you prefer the allow list template instead of the deny list, see community template:
@@ -96,4 +101,4 @@ go.work.sum
 
 # Editor/IDE
 # .idea/
-# .vscode/
+# .vscode/