feat(ui): fold the Workflows page into Dashboard → Analytics → Workflow

The workflow analytics now render under the Analytics tab's Workflow
sub-tab; ?tab= and ?sub= deep-link the Dashboard, /workflows redirects there,
and the sidebar drops its Workflows item.

client/README.md

@@ -75,11 +75,10 @@ graph TB
             Layout[Layout Component]
             
             subgraph "Pages"
-                Home[Dashboard<br/>Monitor / Analytics / Health tabs]
+                Home[Dashboard<br/>Monitor / Analytics (incl. Workflow) / Health tabs]
                 Sessions[Sessions]
                 Detail[SessionDetail]
                 Feed[ActivityFeed]
-                Workflows[Workflows]
                 Settings[Settings]
             end
             
@@ -106,7 +105,7 @@ graph TB
     end
     
     Router --> Layout
-    Layout --> Home & Sessions & Detail & Feed & Workflows & Settings
+    Layout --> Home & Sessions & Detail & Feed & Settings
     Home & Detail --> AgentCard & StatCard & StatusBadge
     Feed --> EventDetail
     API --> REST
@@ -198,14 +197,14 @@ client/
 │   │   │   ├── HomeDirSetting.tsx           # CLAUDE_HOME / CODEX_HOME editor (env-owned warning)
 │   │   │   ├── CodexHooksSettings.tsx       # Codex → Overview → Codex hooks card
 │   │   │   └── AntigravityHooksSettings.tsx # Antigravity → Antigravity hooks card
-│   │   └── workflows/      # Workflows page panels: own-pipeline stats + D3 analytics (11 files)
+│   │   └── workflows/      # Dashboard → Analytics → Workflow panels: own-pipeline stats + D3 analytics (11 files)
 │   │
 │   ├── pages/              # Route pages
 │   │   ├── Dashboard.tsx      # Monitor / Analytics / Health tabs
 │   │   ├── Sessions.tsx       # Filterable table; shows each session's real name (synced live from the transcript), falls back to the short ID
 │   │   ├── SessionDetail.tsx  # Agent tree + event timeline + Conversation tab (slash-command pills & output, inline rename markers)
 │   │   ├── ActivityFeed.tsx  # Real-time event log; row click expands payload; Session btn navigates
-│   │   ├── Workflows.tsx
+│   │   ├── Workflows.tsx      # Workflow analytics, rendered in Dashboard → Analytics → Workflow
 │   │   ├── Settings.tsx
 │   │   ├── AiToolConfig.tsx  # Settings → <tool>: the generic tab of every installed, enabled catalog tool (path, Update link, sessions/cost/lanes, default model, vendor pricing, catalog-declared config files; Antigravity adds its hooks card)
 │   │   └── NotFound.tsx
@@ -252,11 +251,12 @@ graph TB
     Sessions[Sessions<br/>filterable table]
     Detail[SessionDetail<br/>agent hierarchy + timeline]
     Feed[ActivityFeed<br/>streaming event log]
-    Workflows[Workflows<br/>Lane pipelines + D3 analytics]
+    Workflows[Workflows<br/>Analytics → Workflow sub-tab:<br/>lane pipelines + D3 analytics]
     Settings[SettingsHub /settings/:section<br/>General · Appearance · Notifications<br/>Agents: AI tools, Claude Code, Codex, each catalog tool<br/>Routing: AI Router, Pricing · Git: credentials, worktrees<br/>Projects: one page per repo]
 
     App --> Layout
-    Layout --> Dashboard & Sessions & Detail & Feed & Workflows & Settings
+    Layout --> Dashboard & Sessions & Detail & Feed & Settings
+    Dashboard --> Workflows
 
     Dashboard --> StatCard[StatCard × 6]
     Dashboard --> AgentCard[AgentCard × N]
@@ -469,7 +469,7 @@ graph TB
     Sessions["/sessions (tabs: sessions | events)"]
     Detail["/sessions/:id"]
     Feed["/activity (redirect)"]
-    Workflows["/workflows"]
+    Workflows["/workflows (redirect → /?tab=analytics&sub=workflow)"]
     CcConfig["/cc-config (redirect)"]
     Lanes["/lanes (redirect)"]
     Run["/run (redirect)"]
@@ -500,7 +500,7 @@ function App() {
           <Route path="sessions/:id" element={<SessionDetail />} />
           {/* legacy path - the activity feed is now a tab on /sessions */}
           <Route path="activity" element={<Navigate to="/sessions?view=events" replace />} />
-          <Route path="workflows" element={<Workflows />} />
+          <Route path="workflows" element={<Navigate to="/?tab=analytics&sub=workflow" replace />} />
           {/* legacy path - Claude config now lives in a Settings tab */}
           <Route path="cc-config" element={<Navigate to="/settings/agents/claude-code" replace />} />
           {/* legacy paths - lanes and runs are one page now */}