feat: safe area fix, delete from repo, add Mistral provider

- Wrap root layout with SafeAreaProvider, use useSafeAreaInsets in all
  screens so FAB/action bar/scroll content clear Android nav bar
- Add deleteIncidentFromGit() (Gitea/GitHub/GitLab) — detail screen now
  offers Cancel / Local only / Local + Repo when incident was pushed
- Add Mistral as AI provider (OpenAI-compat, api.mistral.ai/v1,
  mistral-small-latest default)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/_layout.tsx

@@ -3,6 +3,7 @@ import { Pressable, Text } from "react-native";
 import { Stack, router } from "expo-router";
 import { StatusBar } from "expo-status-bar";
 import { GestureHandlerRootView } from "react-native-gesture-handler";
+import { SafeAreaProvider } from "react-native-safe-area-context";
 import "../global.css";
 import { Colors } from "@/constants/theme";
 import { useSettings } from "@/hooks/useSettings";
@@ -18,6 +19,7 @@ export default function RootLayout() {
   }, [ready, settings.onboardingDone]);
 
   return (
+    <SafeAreaProvider>
     <GestureHandlerRootView style={{ flex: 1, backgroundColor: Colors.bg }}>
       <StatusBar style="light" />
       <Stack
@@ -49,5 +51,6 @@ export default function RootLayout() {
         <Stack.Screen name="onboarding" options={{ headerShown: false }} />
       </Stack>
     </GestureHandlerRootView>
+    </SafeAreaProvider>
   );
 }