replace EasyMDE (333KB) with OverType (118KB) in pages-edit.php

- Remove easymde.min.js (320KB) and easymde.min.css (13KB)
- Vendor overtype.min.js (118KB, v2.3.5)
- Replace <textarea name=content> + 60-line toolbar/SVG init with:
  - <input type=hidden name=content> for form submission
  - <div id=editor> as OverType mount target
  - 6-line init: value from hidden input, onChange syncs it back
- Net saving: ~215KB assets, ~54 lines of inline JS

TODO.md

@@ -11,6 +11,8 @@ Pending tasks have been split into topic files under [`todo/`](todo/README.md):
 
 ## Recently completed (this session)
 
+- [x] `pages-edit.php` — replaced EasyMDE (333 KB: 320 KB JS + 13 KB CSS) with OverType (118 KB, single JS file, no CSS); removed `easymde.min.js` and `easymde.min.css` from `public/assets/`; vendored `overtype.min.js`; replaced `<textarea name="content">` + 60-line EasyMDE toolbar/SVG init block with `<input type="hidden" name="content">` + `<div id="editor">` mount target + 6-line OverType init; `onChange` callback keeps the hidden input in sync for form submission; net saving: ~215 KB, ~54 lines of JS
+
 - [x] `templates/header.php` + `admin.css` — extracted last remaining inline `style=` from any shared template: `style="vertical-align:middle;margin-right:0.4em"` on the admin-nav public-site SVG icon moved to `.admin-body header nav > a svg` rule in `admin.css`; `templates/header.php` now contains zero `style=` attributes; only the dynamic gradient (`hsl(<?= $hue ?>)`) in `public/index.php` and the PHP-runtime `--disk-pct`/`--disk-color` custom properties in `system.php` remain (both legitimately dynamic)
 
 - [x] `admin/thanks.php` + `admin/pages.php` + `admin.css` — extracted last 3 inline `style=` attributes from admin PHP templates: `<div style="margin-top:1.5rem;display:flex;gap:.75rem;flex-wrap:wrap;">` in `thanks.php` → `class="admin-action-bar"` (`.admin-action-bar` rule added to CSS); `<p style="color:var(--text-secondary);">` in `thanks.php` → `class="admin-muted"` (`.admin-muted` rule added); `style="font-size:.8rem;padding:.3rem .75rem;"` on Éditer button in `pages.php` → `class="admin-btn admin-btn--sm"` (uses existing modifier). Only the dynamic `--disk-pct`/`--disk-color` CSS custom properties on the disk bar in `system.php` remain (carry PHP runtime values — legitimate).