docs: source badge name only, no signals lock, the Add-a-signal page

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

docs/claude/invariants-gtk-and-chrome.md

@@ -255,8 +255,8 @@ Part of [CLAUDE.md](../../CLAUDE.md). These are rules that cost a defect to lear
   `gtk_box_reorder_child_after` and rewrites `App::badge_order` from the widgets, and **never rebuilds the badges** --
   the dragged badge and the target whose `drop` emission is running must both survive it. A foreign drag whose string is not a
   signal index is refused. `[sigbadges]` reads the controllers, the payload and the reorder; `pane drag:` reads the close.
-- **A stock icon name has to be one *Adwaita* has, and a blank button is the failure mode.** The two
-  panes' `[edit]` buttons are `document-edit-symbolic` (the pencil: edit) and `object-select-symbolic`
+- **A stock icon name has to be one *Adwaita* has, and a blank button is the failure mode.** The
+  trigger pane's `[edit]` button is `document-edit-symbolic` (the pencil: edit) and `object-select-symbolic`
   (the check: done). The done one was `emblem-ok-symbolic`, which breeze ships and **Adwaita does not** —
   so the button that leaves configuration mode was blank, which no other reading could see: the button
   worked, the layout was unchanged, and only `pane edits:` (the two names and