feat(spec): progressive-disclosure popover for composite form fields

Adds `disclosure?: 'inline' | 'popover'` to FormFieldSchema. A composite field
marked `disclosure: 'popover'` renders as a compact summary line + a gear that
opens its sub-fields in a popover (Airtable-style progressive disclosure),
instead of an always-expanded inline box — keeping the interface-page panel lean.

Applied to the page form's `appearance`, `userActions`, and `addRecord`
composites (the dense sub-toggle groups).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: os-zhuang

packages/spec/src/ui/page.form.ts

@@ -95,16 +95,16 @@ export const pageForm = defineForm({
             { field: 'filterBy', type: 'repeater', helpText: 'Always-on base filter for the page' },
             { field: 'levels', helpText: 'Hierarchy levels to display (tree-like sources)' },
             // ── Appearance ──
-            { field: 'appearance', type: 'composite', helpText: 'Allowed visualizations (Grid / Kanban / Calendar / …) and description visibility' },
+            { field: 'appearance', type: 'composite', disclosure: 'popover', helpText: 'Allowed visualizations (Grid / Kanban / Calendar / …) and description visibility' },
             // ── User filters ──
             {
               field: 'userFilters',
               widget: 'filter-mode',
               helpText: 'End-user filter bar: None (no bar) / Tabs (named presets) / Dropdown (per-field). None removes the config.',
             },
             // ── User actions ──
-            { field: 'userActions', type: 'composite', helpText: 'Toolbar toggles (search, sort, filter, row height)' },
-            { field: 'addRecord', type: 'composite', helpText: 'Add-record entry point' },
+            { field: 'userActions', type: 'composite', disclosure: 'popover', helpText: 'Toolbar toggles (search, sort, filter, row height)' },
+            { field: 'addRecord', type: 'composite', disclosure: 'popover', helpText: 'Add-record entry point' },
             { field: 'showRecordCount', helpText: 'Show the record count bar' },
             { field: 'allowPrinting', helpText: 'Allow users to print this page' },
           ],

packages/spec/src/ui/view.zod.ts

@@ -715,6 +715,7 @@ export const FormFieldSchema: z.ZodType<any> = lazySchema(() => z.object({
 
   dependsOn: z.string().optional().describe('Parent field name for cascading'),
   visibleOn: ExpressionInputSchema.optional().describe('Visibility predicate (CEL).'),
+  disclosure: z.enum(['inline', 'popover']).optional().describe('Composite rendering: inline bordered box (default) or a summary line + gear popover (progressive disclosure).'),
 }));
 
 /**