v1.4

Add graphical editor (SidebarCardEditor) with YAML card support

• New SidebarCardEditor component: full visual UI to configure sidebar
  and header without editing YAML manually; opens via toolbar button
  or gear icon in sidebar (admin only)
• All card slot editors (bottomCard, leftCard, centerCard, rightCard,
  stack items, service_data) now use YAML format instead of JSON
• Add yaml library for reliable YAML parse/stringify
• saveLovelaceConfig helper in helpers.ts for WebSocket config save
• Toolbar button injected into HA top bar for admin users
• Fix frozen config object mutation after WS save
• Reset ALREADY_BUILT on dashboard navigation change
• Update README.md and README.it.md with editor documentation