Merge branch 'main' into optimize-anchored-overlay=2

Author: hectahertz

.changeset/cyan-tigers-reply.md

@@ -0,0 +1,5 @@
+---
+'@primer/mcp': minor
+---
+
+Adds support for fetching docs via the `/llms.txt` endpoint per-component

.changeset/dry-carrots-bathe.md

@@ -0,0 +1,45 @@
+---
+'@primer/react': minor
+---
+
+Add `currentWidth` and `onResizeEnd` props to PageLayout.Pane for controlled resizable width
+
+The `PageLayout.Pane` component now supports controlled width:
+
+- `onResizeEnd` — callback fired when a resize operation ends (pointer release or keyboard key up). Replaces localStorage persistence. Requires `currentWidth`.
+- `currentWidth` — sets the current displayed width in pixels (`number | undefined`). Pass `undefined` when the persisted value hasn't loaded yet. Requires `onResizeEnd`.
+
+Both props must be provided together (enforced by TypeScript). `resizable` remains a plain `boolean` prop.
+
+These props are only meaningful when `resizable={true}` — without it, no drag handle renders so `onResizeEnd` never fires.
+
+**New export:**
+
+- `defaultPaneWidth` — Record of preset width values: `{small: 256, medium: 296, large: 320}`
+
+**Example usage:**
+
+```tsx
+import {PageLayout, defaultPaneWidth} from '@primer/react'
+
+// Default behavior (unchanged) — localStorage persistence
+<PageLayout.Pane resizable />
+
+// Controlled width with custom persistence
+const [width, setWidth] = useState(defaultPaneWidth.medium)
+<PageLayout.Pane
+  resizable
+  currentWidth={width}
+  onResizeEnd={(newWidth) => {
+    setWidth(newWidth)
+    myStorage.save('pane-width', newWidth)
+  }}
+/>
+
+// Async load — pass undefined until value is fetched
+<PageLayout.Pane
+  resizable
+  currentWidth={savedWidth ?? undefined}
+  onResizeEnd={handleResizeEnd}
+/>
+```

.changeset/fast-pots-say.md

@@ -0,0 +1,5 @@
+---
+"@primer/react": patch
+---
+
+Update PageHeader story to have semantic headings

.changeset/fix-scroll-jump-on-resize.md

@@ -0,0 +1,5 @@
+---
+"@primer/react": patch
+---
+
+fix: ActionBar overflow menu not closing on select

.changeset/gold-snakes-smash.md

@@ -17,7 +17,7 @@ jobs:
       matrix:
         shard: [1, 2, 3, 4, 5, 6, 7, 8]
     steps:
-      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd
       - name: Set up Node.js
         uses: actions/setup-node@395ad3262231945c25e8478fd5baf05154b1d79f
         with:
@@ -63,7 +63,7 @@ jobs:
     runs-on: ubuntu-latest
     needs: aat-runner
     steps:
-      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd
       - name: Set up Node.js
         uses: actions/setup-node@395ad3262231945c25e8478fd5baf05154b1d79f
         with: