Add Users, media library, navigation menus from the scan, new-page wizard and deleted-page recovery

Users (Tools > Users)
- Everyone can update their display name, email and password; administrators can add,
  edit, invite (one-time link), block and delete accounts.
- Accounts in config.local.php stay locked to config (the main administrator); CMS
  accounts live in data/users.json. Sign-in is by login name.
- Roles are now editor and administrator (publisher is an alias of editor).
- Account protection: password hashes only (12-72 characters), administrator password
  confirmation for sensitive actions, rate-limited failures, hashed single-use invite
  tokens, self-lockout guards, sessions of blocked/deleted users end on the next request,
  every account event audited without secrets.
- dataDirectory can move data outside the web root; the dashboard recommends it.

Media library
- Upload images, documents, video and audio, sorted into four categories by extension.
- Extension allow-list; executables, scripts, HTML/SVG, archives, legacy and macro Office
  files refused; content sniffing; files containing code refused; PDFs with scripts refused;
  Office/OpenDocument packages inspected for macros and embedded objects.
- Media library button in the editor inserts an image, document link, video or audio.

Navigation menus, pages and interface
- The site scan detects primary/secondary navigation and seeds Navigation Menus; menus can be
  renamed, edited and deleted but not created by the CMS; a scan button finds new navigation.
- New page wizard (template, name, navigation group) in the Pages dialogue; new pages stay
  private drafts until published; pages can be used as templates.
- Deleted pages can be recovered from the Dashboard.
- Full-width top bar with the user at the top right, device icons, consistent buttons.

Tests and docs updated (tests/run.php, README, ARCHITECTURE, DEVELOPMENT, CHANGELOG).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

uploads/.htaccess

@@ -1,7 +1,7 @@
-# Uploaded files are images only; deny executable extensions even if one appears by other means.
-Options -Indexes
+# Uploaded media: images, documents, video and audio only. Deny executable and markup extensions even if one appears by other means.
+Options -Indexes -ExecCGI
 
-<FilesMatch "\.(?:php[0-9]?|phtml|phar|cgi|pl|py|sh)$">
+<FilesMatch "\.(?:php[0-9]?|phtml|phar|cgi|pl|py|sh|exe|dll|bat|cmd|com|msi|asp|aspx|jsp|jspx|html?|xhtml|shtml|svg|xml|js|jar|swf)$">
     Require all denied
 </FilesMatch>
 
@@ -9,4 +9,8 @@ Options -Indexes
     Header always set X-Content-Type-Options "nosniff"
     Header always set Content-Security-Policy "default-src 'none'; sandbox"
     Header always set Cross-Origin-Resource-Policy "same-origin"
+    # Documents download instead of rendering in the browser.
+    <FilesMatch "\.(?:pdf|docx|xlsx|pptx|odt|ods|odp|txt|csv)$">
+        Header always set Content-Disposition "attachment"
+    </FilesMatch>
 </IfModule>