fix: use full width for supervisor recap and activity

Remove the extra reading and dashboard width caps so recap controls, results, and activity details fill the supervisor panel. Update layout assertions and UI documentation.

Release note: 修复监督者工作回顾与活动记录页面偏窄的问题，内容现在铺满页签下方的可用宽度。

tests/support/supervisor-layout-driver.mjs

@@ -83,7 +83,7 @@ app
             const report = await js(`(() => {
               const box = selector => { const r = document.querySelector(selector)?.getBoundingClientRect(); return r && { left:r.left, right:r.right, width:r.width, height:r.height }; };
               return { width:innerWidth, pageWidth:document.documentElement.scrollWidth,
-                toolbar:box('.supervisor-workspace__toolbar'), history:box('.supervisor-workspace__result-navigation'), recap:box('.supervisor-workspace__recap'),
+                panel:box('.heartbeat-center > [role=tabpanel]:not([hidden])'), toolbar:box('.supervisor-workspace__toolbar'), history:box('.supervisor-workspace__result-navigation'), recap:box('.supervisor-workspace__recap'),
                 prose:box('.supervisor-workspace__prose'), activity:box('.supervisor-activity'),
                 steps:box('.supervisor-activity__steps'),
                 summaryLength:[...document.querySelectorAll('.supervisor-workspace__summary')].map(e=>e.textContent).join('').length,
@@ -93,13 +93,13 @@ app
             assert(report.pageWidth <= width, 'No page overflow')
             if (view !== 'activity') {
               assert(report.summaryLength > 2000 && report.tail, 'Long summary retained')
-              assert(report.recap.width <= 820, 'Whole recap uses reading frame')
+              assert(Math.abs(report.recap.width - report.panel.width) < 1, 'Recap fills the page panel')
               for (const control of [report.toolbar, report.history]) {
                 assert(Math.abs(control.left - report.recap.left) < 1 && Math.abs(control.right - report.recap.right) < 1, 'Toolbar, history and result share edges')
               }
               assert(report.prose.left - report.recap.left <= 25, 'No separately centered inner body')
             } else {
-              assert(report.activity.width <= 1040, 'Activity dashboard frame')
+              assert(Math.abs(report.activity.width - report.panel.width) < 1, 'Activity fills the page panel')
               if (width >= 1024) {
                 assert(report.steps.height < 40, 'Compact stage row')
                 assert(report.controls[2].left - report.controls[1].right <= 24, 'Refresh grouped with filter')
@@ -217,7 +217,7 @@ app
               if (scenario !== 'empty') {
                 assert.equal(report.paragraphs, 4)
                 assert(report.text.includes('外部评审时间') && report.text.includes('未解决事项'))
-                if (width === 1440) assert(report.proseWidth < 820, 'Bounded prose width')
+                assert(report.clientWidth - report.proseWidth <= 50, 'Prose fills the panel within card padding')
               } else assert(report.text.includes('还没有成功回顾'))
             } else {
               assert.equal(report.text.includes('暂无自动监督报告'), scenario !== 'populated')