fix: align supervisor settings layout and default model naming

Group settings tabs and forms in a single surface with consistent spacing. Rename the model section to cover model selection and execution limits, and use Default model for the default connection option.

Release note: 修复监督者设置页签与表单贴边的问题，统一设置布局，并将默认模型选项名称改为默认模型。

src/renderer/src/HeartbeatCenter.test.tsx

@@ -579,10 +579,10 @@ describe('HeartbeatCenter', () => {
       expect(screen.queryByRole('heading', { name })).not.toBeInTheDocument()
     }
     fireEvent.click(screen.getByRole('tab', { name: '设置' }))
-    expect(screen.getByRole('heading', { level: 2, name: '模型超时与并发' })).toBeInTheDocument()
+    expect(screen.getByRole('heading', { level: 2, name: '模型与运行限制' })).toBeInTheDocument()
     fireEvent.click(screen.getByRole('tab', { name: '回顾整理' }))
     expect(screen.getByRole('heading', { level: 2, name: '回顾算法' })).toBeInTheDocument()
-    expect(screen.queryByRole('heading', { name: '模型超时与并发' })).not.toBeInTheDocument()
+    expect(screen.queryByRole('heading', { name: '模型与运行限制' })).not.toBeInTheDocument()
     fireEvent.click(screen.getByRole('tab', { name: '故事与经验' }))
     expect(screen.getByRole('switch', { name: '跨项目关联' })).toBeVisible()
     fireEvent.click(screen.getByRole('tab', { name: '建议' }))
@@ -691,7 +691,7 @@ describe('HeartbeatCenter', () => {
     expect(screen.queryByRole('region', { name: '心跳计划' })).not.toBeInTheDocument()
     fireEvent.click(screen.getByRole('tab', { name: '设置' }))
     expect(screen.getAllByRole('heading', { level: 1 })).toHaveLength(1)
-    expect(screen.getByRole('heading', { name: '模型超时与并发' })).toBeInTheDocument()
+    expect(screen.getByRole('heading', { name: '模型与运行限制' })).toBeInTheDocument()
   })
 
   it('keeps an unsaved draft when switching settings tabs', () => {

src/renderer/src/i18n/locales/en-US/heartbeat.ts

@@ -44,10 +44,10 @@ export const heartbeat = {
   },
   timeouts: {
     model: 'Model',
-    followDefault: 'Follow app default',
+    followDefault: 'Default model',
     unavailableModel: 'Selected model is unavailable',
     modelHelp: 'Uses an existing text model for reviews, summaries, stories, experiences, and suggestions. Saving affects the next execution, including continue or retry; a review already running keeps its model.',
-    title: 'Model timeouts and concurrency',
+    title: 'Model and execution limits',
     report: 'Heartbeat report timeout (seconds)',
     organize: 'Supervisor organize timeout (seconds)',
     help: 'The organize timeout defaults to 240 seconds, adjustable from 30 to 600. Reviews save it at creation and retain it when continued; suggestions use the same limit.',

src/renderer/src/i18n/locales/zh-CN/heartbeat.ts

@@ -41,10 +41,10 @@ export const heartbeat = {
   },
   timeouts: {
     model: '模型',
-    followDefault: '跟随应用默认',
+    followDefault: '默认模型',
     unavailableModel: '所选模型已不可用',
     modelHelp: '复用已有文本模型，用于回顾、汇总、故事、经验和建议。保存后从下次执行生效，包括继续或重试；正在运行的回顾保持原模型。',
-    title: '模型超时与并发',
+    title: '模型与运行限制',
     report: '心跳报告超时（秒）',
     organize: '监督者整理超时（秒）',
     help: '整理超时默认 240 秒，可设置为 30 至 600 的整数秒。回顾在创建时保存整理超时，继续时沿用；生成建议使用同一上限。',

src/renderer/src/supervisor-workspace.css

@@ -1116,6 +1116,36 @@
   gap: var(--space-3);
 }
 
+.supervisor-settings {
+  display: flex;
+  flex: 0 0 auto;
+  min-width: 0;
+  flex-direction: column;
+  gap: var(--space-6);
+  padding: var(--space-4);
+  border: 1px solid var(--border-default);
+  border-radius: var(--radius-card);
+  background: var(--surface-raised);
+}
+
+.supervisor-settings > .page-tabs {
+  align-self: flex-start;
+}
+
+.supervisor-settings .heartbeat-settings__editor {
+  padding: 0;
+  border: 0;
+  border-radius: 0;
+  background: transparent;
+  gap: var(--space-4);
+  overflow-wrap: anywhere;
+}
+
+.supervisor-settings .heartbeat-settings__editor > p {
+  margin: 0;
+  color: var(--text-secondary);
+}
+
 .supervisor-center__sections .heartbeat-settings__editor > h2 {
   margin: 0;
   font-size: var(--font-section-title);
@@ -1326,4 +1356,4 @@
   margin: var(--space-1) 0 0;
   padding-inline-start: 1.1em;
   color: var(--text-muted);
-}
+}