Add a real replacement Posts management page (v2.5.0)

Posts was previously just dark-themed skinning over the native
edit.php list table, unlike Comments/Plugins which are genuine
replacements. Built the same way: new PostsData.php REST controller
(list with status/search filters matching native tabs, trash, restore,
permanent delete) and a Vue page matching the Comments layout.

- SubApps.php registers it as aurora-admin-posts, parented under
  edit.php (same pattern as Plugins under plugins.php).
- redirect_native_pages() redirects direct edit.php visits (typed URL,
  not just the sidebar link) to the Aurora page — gated to the default
  post type only, so Pages and other custom post types are untouched.
- MenuSerializer rewrites the sidebar's Posts/All Posts links the same
  way Plugins/Comments already were.
- Gated by Settings > Posts' "Modern posts table" toggle, re-added now
  that it has a real implementation (it was removed a few commits ago
  for describing a feature that didn't exist).
- Fixed modern_plugins/modern_comments/modern_posts all defaulting to
  visually "on" in the Settings UI to match their actual PHP default.

Verified live: trash/restore/status filters/search all work correctly,
edit.php redirects to the Aurora page, edit.php?post_type=page (Pages)
correctly does not.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

CHANGELOG.md

@@ -5,6 +5,27 @@ version bump. Starts at 2.1.0 — earlier history (the theming rebuild,
 window chrome/taskbar, Site Editor support, etc.) lives in `git log` and
 `PROJECT_STATUS.md`, not reconstructed here.
 
+## [2.5.0] - 2026-07-05
+
+### Added
+- Real replacement Posts management page (`aurora-admin-posts`), the same
+  kind of full custom page as Comments/Plugins rather than dark-themed
+  skinning over the native `edit.php` list table. New `PostsData.php` REST
+  controller (list with status/search filters, trash, restore, permanent
+  delete) and a new Vue page matching the Comments layout (status filter
+  pills, search, table with title/author/categories/comments/date/status,
+  inline row actions, pagination). The native Posts screen (`edit.php`,
+  default post type only — Pages and other post types are untouched)
+  redirects to it, gated by Settings > Posts' restored "Modern posts
+  table" toggle (removed a few commits ago when it had no implementation
+  behind it — now it does).
+
+### Fixed
+- The `modern_plugins`/`modern_comments` settings toggles now default to
+  visually "on" in the Settings UI to match their actual PHP default
+  (previously they defaulted true server-side but showed off in the UI
+  until explicitly saved) — same fix applied to the new `modern_posts`.
+
 ## [2.4.2] - 2026-07-04
 
 ### Fixed