feat: Implement The Commuter demo screens (#31)

Implement 4 new screens for "The Commuter" demo showcasing async-first
workflows with transparent session mobility. This implementation includes:

**Screens Implemented:**
- ACP Inbox (app/(tabs)/inbox.tsx) - Homescreen with summary stats, stuck
  agent banner, decision queue card, overnight results, and forecast
- Decision Queue (app/decisions/index.tsx) - List of pending decisions
- Review Flow (app/decisions/[id].tsx) - 3-step review process with soft
  gates, accordion tracking, quick response chips
- Notification History (app/notifications/history.tsx) - Date-grouped
  notifications with restore functionality

**Components Created:**
- Inbox: InboxHeader, StuckAgentBanner, DecisionQueueCard,
  OvernightResultsCard, ForecastCard
- Decisions: DecisionCard
- UI: AgentAvatar, NotificationStatusBadge

**Types & Mock Data:**
- types/inbox.ts: InboxSummary, StuckAgent, OvernightResult, Forecast,
  Notification, AgentName, AGENT_COLORS
- types/decisions.ts: PendingDecision, DecisionDetails, AccordionSection,
  ReviewFlow
- utils/mockInboxData.ts: Complete mock data for all 4 screens with
  easter egg (RFE #67)

**Navigation:**
- Added Inbox tab to main navigation
- Created decisions stack navigation
- All screens support pull-to-refresh

**Features:**
- No one-click approvals (enforced via "Start Review" flow)
- 3-step review process with soft gate (must view all sections)
- Quick response chips ("Looks good", "Needs discussion", "Try different")
- Notification restore functionality (DISMISSED → RESTORED)
- Agent-colored avatars (Parker=blue, Archie=purple, Taylor=green,
  Phoenix=orange, Morgan=red)
- Responsive to light/dark theme

Implements: #28

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Ambient Code Bot <bot@ambient-code.local>
Co-authored-by: Claude <noreply@anthropic.com>

Author: 3 people

app/(tabs)/_layout.tsx

@@ -37,10 +37,17 @@ export default function TabLayout() {
       <Tabs.Screen
         name="index"
         options={{
-          title: 'Home',
+          title: 'Sessions',
           tabBarIcon: ({ color }) => <IconSymbol size={28} name="house.fill" color={color} />,
         }}
       />
+      <Tabs.Screen
+        name="inbox"
+        options={{
+          title: 'Inbox',
+          tabBarIcon: ({ color }) => <IconSymbol size={28} name="tray.fill" color={color} />,
+        }}
+      />
       <Tabs.Screen
         name="explore"
         options={{

app/(tabs)/inbox.tsx

@@ -0,0 +1,58 @@
+import React, { useState } from 'react'
+import { View, ScrollView, RefreshControl, StyleSheet } from 'react-native'
+import { InboxHeader } from '@/components/inbox/InboxHeader'
+import { StuckAgentBanner } from '@/components/inbox/StuckAgentBanner'
+import { DecisionQueueCard } from '@/components/inbox/DecisionQueueCard'
+import { OvernightResultsCard } from '@/components/inbox/OvernightResultsCard'
+import { ForecastCard } from '@/components/inbox/ForecastCard'
+import { mockInboxData, mockPendingDecisions } from '@/utils/mockInboxData'
+import { useTheme } from '@/hooks/useTheme'
+
+export default function InboxScreen() {
+  const { colors } = useTheme()
+  const [refreshing, setRefreshing] = useState(false)
+
+  const onRefresh = async () => {
+    setRefreshing(true)
+    // Simulate fetch delay
+    await new Promise((resolve) => setTimeout(resolve, 500))
+    setRefreshing(false)
+  }
+
+  const { user, summary, stuckAgents, overnightResults, forecast } = mockInboxData
+
+  // Calculate total minutes for decision queue
+  const totalMinutes = mockPendingDecisions.reduce(
+    (sum, decision) => sum + decision.estimatedMinutes,
+    0
+  )
+
+  return (
+    <ScrollView
+      style={[styles.container, { backgroundColor: colors.bg }]}
+      refreshControl={
+        <RefreshControl refreshing={refreshing} onRefresh={onRefresh} tintColor={colors.accent} />
+      }
+      showsVerticalScrollIndicator={false}
+    >
+      <InboxHeader userName={user.name} summary={summary} />
+
+      <StuckAgentBanner agents={stuckAgents} />
+
+      <DecisionQueueCard count={summary.pendingDecisions} totalMinutes={totalMinutes} />
+
+      <OvernightResultsCard results={overnightResults} />
+
+      <ForecastCard forecast={forecast} />
+
+      {/* Bottom padding */}
+      <View style={{ height: 24 }} />
+    </ScrollView>
+  )
+}
+
+const styles = StyleSheet.create({
+  container: {
+    flex: 1,
+  },
+})