View state: hide, show and isolate viewport items, saved with the model

view.hide, view.show, view.isolate and view.show_all change which
bodies, surfaces, datums, boundary conditions, loads, reference points
and couplings the viewport draws. The hidden items are view state: the
manifest's `view` keeps them, a change marks the model unsaved, but it
is neither journalled nor undone and leaves results current. Items that
go away are forgotten. Headless pictures leave hidden items out; the
glyph builders take a filter. Tools > View > Show All claims the
commands.

Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo

assets/icons/src/view.show_all.json

@@ -0,0 +1 @@
+{"shapes": [{"d": "M2.5 13 C5.5 7.5 18.5 7.5 21.5 13 C18.5 18.5 5.5 18.5 2.5 13 Z", "fill": "soft", "stroke": "line"}, {"circle": [12, 13, 2.6], "fill": "accent", "stroke": "accent", "width": 1}, {"d": "M12 2.5 L12 5 M5.5 4.5 L7 6.5 M18.5 4.5 L17 6.5", "stroke": "warm", "width": 1.5}]}

assets/icons/view.show_all.svg

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" width="24" height="24" viewBox="0 0 24 24">
+  <title>view.show_all</title>
+  <g id="Layer_1" data-name="Layer 1">
+    <path d="M2.5 13 C5.5 7.5 18.5 7.5 21.5 13 C18.5 18.5 5.5 18.5 2.5 13 Z" fill="#2d4e70" stroke="#dde2ea" stroke-width="1.5" stroke-linecap="round" stroke-linejoin="round"/>
+    <path d="M9.4 13 C9.4 11.564 10.564 10.4 12 10.4 C13.436 10.4 14.6 11.564 14.6 13 C14.6 14.436 13.436 15.6 12 15.6 C10.564 15.6 9.4 14.436 9.4 13 Z" fill="#4f9ce8" stroke="#4f9ce8" stroke-linecap="round" stroke-linejoin="round"/>
+    <path d="M12 2.5 L12 5 M5.5 4.5 L7 6.5 M18.5 4.5 L17 6.5" fill="none" stroke="#f0b44a" stroke-width="1.5" stroke-linecap="round" stroke-linejoin="round"/>
+  </g>
+</svg>