feat(mobile): Containr companion app — Expo/RN thin client

Phone app v1 (Phase I): PAT auth against any instance, secure-store
credentials, dark UI matching the design system.

- Overview: service status counts, per-project health dots, deploy feed
- Services/Projects: status badges, drill-down detail
- Service detail: start/stop/restart/redeploy/sleep/wake, env-doctor
  issues, deployment history + rollback
- Logs: 300-line tail, 5s poll, stderr highlighted
- Databases: status, start/stop/restart, backup-now
- Settings: server info, disconnect

CI: mobile job (tsc + expo lint) gated on a dedicated app/mobile paths
filter so non-mobile PRs skip it entirely.

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

app/mobile/src/app/(tabs)/_layout.tsx

@@ -0,0 +1,55 @@
+import React from 'react';
+import { Tabs } from 'expo-router';
+import { Ionicons } from '@expo/vector-icons';
+import { colors } from '../../theme';
+
+export default function TabsLayout() {
+  return (
+    <Tabs
+      screenOptions={{
+        headerStyle: { backgroundColor: colors.bg },
+        headerTintColor: colors.text,
+        tabBarStyle: { backgroundColor: colors.surface, borderTopColor: colors.border },
+        tabBarActiveTintColor: colors.accent,
+        tabBarInactiveTintColor: colors.textDim,
+      }}
+    >
+      <Tabs.Screen
+        name="index"
+        options={{
+          title: 'Overview',
+          tabBarIcon: ({ color, size }) => (
+            <Ionicons name="grid-outline" size={size} color={color} />
+          ),
+        }}
+      />
+      <Tabs.Screen
+        name="services"
+        options={{
+          title: 'Services',
+          tabBarIcon: ({ color, size }) => (
+            <Ionicons name="cube-outline" size={size} color={color} />
+          ),
+        }}
+      />
+      <Tabs.Screen
+        name="databases"
+        options={{
+          title: 'Databases',
+          tabBarIcon: ({ color, size }) => (
+            <Ionicons name="server-outline" size={size} color={color} />
+          ),
+        }}
+      />
+      <Tabs.Screen
+        name="settings"
+        options={{
+          title: 'Settings',
+          tabBarIcon: ({ color, size }) => (
+            <Ionicons name="settings-outline" size={size} color={color} />
+          ),
+        }}
+      />
+    </Tabs>
+  );
+}