ux: replace generic cog admin-menu icon with closed-book (v3.3.5)

The WordPress admin sidebar showed "Logbook" with the generic
cog wheel icon (dashicons-admin-generic) — fine for a settings
page, off-brand for a plugin whose entire identity is "logbook".

Swapped to dashicons-book-alt (closed book) — the most literal
possible match in the Dashicons set, and visually reinforces the
brand at the first place users see the plugin every day.

Alternatives also viable (commented in the changelog for future
reference): dashicons-edit (pencil), dashicons-clipboard,
dashicons-welcome-write-blog, dashicons-format-aside.

VERSION
- wp-notes.php header 3.3.4 → 3.3.5
- WP_NOTES_VERSION constant 3.3.4 → 3.3.5
- About page version-history leads with v3.3.5; v3.3.4 demoted.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

CHANGELOG.md

@@ -9,6 +9,31 @@ Format: [Keep a Changelog 1.1.0](https://keepachangelog.com/en/1.1.0/) — versi
 
 ---
 
+## [3.3.5] — 2026-05-25
+
+### Changed — Admin-menu icon
+The WordPress admin sidebar icon for Logbook is now
+**`dashicons-book-alt`** (a closed book) instead of the generic
+cog wheel (`dashicons-admin-generic`). The closed-book glyph is the
+most literal possible match for the word "logbook" in the Dashicons
+set — reinforces the brand identity at the first place users see
+the plugin every day.
+
+If you'd prefer a different icon, the line lives in
+`wp-notes.php → wp_notes_admin_menu()` as the 7th arg to
+`add_menu_page()`. Alternatives worth considering:
+`dashicons-edit` (pencil), `dashicons-clipboard` (clipboard),
+`dashicons-welcome-write-blog` (pencil over paper),
+`dashicons-format-aside` (notes glyph). Full list at
+https://developer.wordpress.org/resource/dashicons/
+
+### Version bump
+- wp-notes.php header 3.3.4 → 3.3.5
+- WP_NOTES_VERSION constant 3.3.4 → 3.3.5
+- About page version-history leads with v3.3.5; v3.3.4 demoted.
+
+---
+
 ## [3.3.4] — 2026-05-25
 
 **Repo renamed on Gitea: `a-wp-notes-v3` → `a-logbook`.** Also the