Companion Buttons 1.1.0: pages in the ＋ picker, buttons chosen on the tile

The picker row (page list, Clear, Done) is gone. Each Companion page is now
its own ＋ entry, titled with the page's name, showing the whole page minus
page up/down. The grid icon switches the tile to choosing: click buttons to
take them out or put them back, click the icon again when done. The gear
holds one switch, Page layout (Companion's rows and columns, or packed).

- Tiles follow their page by Companion's page id and buttons by row/column,
  so inserted pages and re-imported pages keep showing.
- A tile remounted after a settings change asks GET /state for the snapshot
  the already-open stream sent, instead of waiting blank.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

companion.js

@@ -8,8 +8,9 @@
  *
  *   pages.watch                 → every page, its name, and which control
  *                                 sits at each row/column
- *   preview.graphics.controlId  → a button's rendered image, following the
- *                                 button if it is moved to another page
+ *   preview.graphics.controlId  → a button's rendered image, on every redraw
+ *   controls.watchControl       → a button's setup, read once for its kind
+ *                                 (page up/down buttons are left out)
  *
  * Nothing here can press, edit or change anything in Companion.
  *
@@ -245,7 +246,7 @@ function createPageBook() {
           }
         }
         buttons.sort((a, b) => a.row - b.row || a.column - b.column);
-        return { number: i + 1, name: pageName(page.name, i + 1), buttons };
+        return { id, number: i + 1, name: pageName(page.name, i + 1), buttons };
       })
       .filter(Boolean);
   }
@@ -266,17 +267,16 @@ function createPageBook() {
     return null;
   }
 
-  /** The control at a page number, row and column right now, or null. */
-  function at(number, row, column) {
-    const page = pages.get(order[number - 1]);
-    return (page && page.controls[row] && page.controls[row][column]) || null;
+  /** One page by Companion's own page id (stable when pages are renumbered), or null. */
+  function page(id) {
+    return list().find((p) => p.id === id) || null;
   }
 
   return {
     apply,
     list,
     locate,
-    at,
+    page,
     get loaded() {
       return order.length > 0;
     },
@@ -303,4 +303,7 @@ function pageName(raw, number) {
   return `${number} ${name}`;
 }
 
-module.exports = { createLink, createPageBook, pageName };
+/** Companion's navigation buttons: page up, page down, the page number. Never shown. */
+const NAV_TYPES = new Set(['pageup', 'pagedown', 'pagenum']);
+
+module.exports = { createLink, createPageBook, pageName, NAV_TYPES };