docs: point remaining src/ui.js references at their owners

The README source tree now lists src/ui/ instead of the removed
src/ui.js. docs/CODE-BOUNDARIES.md names src/ui/applicationShell.js as
the owner of panel layout, persistence and share restoration, and
docs/CURRENT-STATE.md places GLOBAL_POST_DEFAULTS in
src/ui/visualPresets.js. QA script comments and test assertion messages
that still named ui.js are updated the same way.

src/scenes/director.test.mjs

@@ -1264,7 +1264,7 @@ test('applyVisualState gates the map-stack switch on both sides of its await', (
   // switch would otherwise stand on the globe.
   const source = readShellSource();
   const method = source.match(/\n {2}async applyVisualState\([\s\S]*?\n {2}\}\n/);
-  assert.ok(method, 'applyVisualState is missing from ui.js');
+  assert.ok(method, 'applyVisualState is missing from the UI shell source');
   assert.match(method[0], /async applyVisualState\(state = \{\}, \{ isCurrent = null \} = \{\}\)/);
 
   const mapStackBlock = method[0].match(/if \(state\.mapStack\) \{[\s\S]*?\n {4}\}/);