fix(layout): per-section footer constraints for multi-section docs (SD-1837)

packages/layout-engine/contracts/src/index.ts

@@ -859,6 +859,17 @@ export type SectionMetadata = {
   titlePg?: boolean;
   /** Vertical alignment of content within this section's pages */
   vAlign?: SectionVerticalAlign;
+  /** Section page margins in CSS px */
+  margins?: {
+    top?: number;
+    right?: number;
+    bottom?: number;
+    left?: number;
+    header?: number;
+    footer?: number;
+  } | null;
+  /** Section page size in CSS px */
+  pageSize?: { w: number; h: number } | null;
 };
 
 export type PageBreakBlock = {

packages/layout-engine/layout-bridge/src/incrementalLayout.ts

@@ -36,6 +36,8 @@ export type HeaderFooterLayoutResult = {
   layout: HeaderFooterLayout;
   blocks: FlowBlock[];
   measures: Measure[];
+  /** Effective layout width when table grid widths exceed section content width (SD-1837). */
+  effectiveWidth?: number;
 };
 
 export type IncrementalLayoutResult = {

packages/layout-engine/painters/dom/src/table/renderTableCell.ts

@@ -1385,11 +1385,7 @@ export const renderTableCell = (deps: TableCellRenderDependencies): TableCellRen
            * indentation but skips marker text rendering).
            */
           const shouldRenderMarker =
-            markerLayout &&
-            markerMeasure &&
-            lineIdx === 0 &&
-            localStartLine === 0 &&
-            markerMeasure.markerWidth > 0;
+            markerLayout && markerMeasure && lineIdx === 0 && localStartLine === 0 && markerMeasure.markerWidth > 0;
 
           if (shouldRenderMarker) {
             // Prepend marker + suffix inside lineEl (mirrors renderer.ts approach)

packages/layout-engine/pm-adapter/src/sections/analysis.test.ts

@@ -846,6 +846,8 @@ describe('analysis', () => {
         footerRefs: { default: 'footer1' },
         numbering: { format: 'decimal' },
         titlePg: false,
+        margins: null,
+        pageSize: null,
       });
     });
 

packages/layout-engine/pm-adapter/src/sections/analysis.ts

@@ -204,6 +204,8 @@ export function publishSectionMetadata(sectionRanges: SectionRange[], options?:
       numbering: section.numbering,
       titlePg: section.titlePg,
       vAlign: section.vAlign,
+      margins: section.margins,
+      pageSize: section.pageSize,
     });
   });
 }

packages/super-editor/src/assets/styles/elements/prosemirror.css

@@ -162,6 +162,18 @@ https://github.com/ProseMirror/prosemirror-tables/blob/master/demo/index.html
   /* width: 100%; */
 }
 
+/* Header/footer editors: constrain table to the editor's available width.
+   Raw DOCX grid <col> widths may exceed the section's content area.
+   table-layout:auto treats col widths as preferred (not hard) constraints,
+   so the browser can redistribute columns to fit within width:100%.
+   !important overrides inline styles set by TableView.updateTable()
+   which resets styles via table.style.cssText. */
+.sd-editor-scoped .ProseMirror.sd-header-footer table {
+  table-layout: auto !important;
+  width: 100% !important;
+  max-width: 100% !important;
+}
+
 .sd-editor-scoped .ProseMirror tr {
   position: relative;
 }

packages/super-editor/src/core/header-footer/EditorOverlayManager.ts

@@ -390,7 +390,7 @@ export class EditorOverlayManager {
         position: 'absolute',
         pointerEvents: 'auto', // Critical: enables click interaction
         visibility: 'hidden', // Hidden by default, shown during editing
-        overflow: 'hidden',
+        overflow: 'visible', // Allow table overflow (page's overflow:hidden still clips at page edge)
         boxSizing: 'border-box',
       });