Maps tab with sharing, walls/doors and strict line of sight

Maps page (list, upload, edit, share, copy), wall/room/door tools in the
map editor, server-side visibility polygon: the image is cut per player
and other tokens are filtered, DM can view as a player, open doors and
switch sight on/off.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HJhXuLD2Z6hv3Wqeq9UL9K

frontend/src/App.jsx

@@ -1,6 +1,7 @@
 import { useEffect, useState } from 'react'
 import Creator from './Creator.jsx'
 import Rules from './Rules.jsx'
+import Maps from './Maps.jsx'
 import Characters from './Characters.jsx'
 import Presets from './Presets.jsx'
 import Lobbies from './Lobbies.jsx'
@@ -54,7 +55,7 @@ export default function App() {
   if (!auth.user) return <main><Login registrationOpen={auth.registration_open} onDone={(u) => setAuth({ ...auth, user: u })} /></main>
 
   const page = hash.split('/')[0]
-  const nav = [['creator', charName ? `Character: ${charName}` : 'Character'], ['rules', 'Rules'], ['presets', 'Presets'], ['characters', 'My characters'], ['lobbies', 'Lobbies'], ...(auth.user.admin ? [['editor', 'Editor']] : [])]
+  const nav = [['creator', charName ? `Character: ${charName}` : 'Character'], ['rules', 'Rules'], ['presets', 'Presets'], ['maps', 'Maps'], ['characters', 'My characters'], ['lobbies', 'Lobbies'], ...(auth.user.admin ? [['editor', 'Editor']] : [])]
 
   return (
     <>
@@ -75,6 +76,7 @@ export default function App() {
         {rules && page === 'creator' && <Creator rules={rules} user={username} loadRequest={loadRequest} clearLoad={() => setLoadRequest(null)} onName={setCharName} />}
         {rules && page === 'rules' && <Rules rules={rules} section={hash.split('/')[1]} />}
         {rules && page === 'presets' && <Presets rules={rules} reload={loadRules} />}
+        {page === 'maps' && <Maps />}
         {rules && page === 'characters' && (
           <Characters onOpen={(entry) => { setLoadRequest(entry); window.location.hash = 'creator' }}
             onNew={() => { setLoadRequest({ new: true }); window.location.hash = 'creator' }} />