feat: add incident delete and clarify AI assistant settings

Wire deleteIncident() into IncidentDetailScreen with a destructive confirm
dialog. Expand the AI settings section with base URL + model fields and an
explanatory card documenting the OpenAI-compatible use case (Ollama / OpenAI).

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

app/settings.tsx

@@ -17,6 +17,8 @@ const KEYS = {
   HOME_VIEW: "pref_home_view",
   AI_ENABLED: "pref_ai_enabled",
   AI_KEY: "pref_ai_key",
+  AI_BASE_URL: "pref_ai_base_url",
+  AI_MODEL: "pref_ai_model",
   MD_TEMPLATE: "md_template",
   GIT_PROVIDER: "git_provider",
   // Gitea
@@ -75,6 +77,8 @@ export default function SettingsScreen() {
   const [homeView, setHomeView] = useState<"dashboard" | "capture">("dashboard");
   const [aiEnabled, setAiEnabled] = useState(false);
   const [aiKey, setAiKey] = useState("");
+  const [aiBaseUrl, setAiBaseUrl] = useState("");
+  const [aiModel, setAiModel] = useState("");
   const [mdTemplate, setMdTemplate] = useState(DEFAULT_TEMPLATE);
   const [saved, setSaved] = useState(false);
 
@@ -97,12 +101,14 @@ export default function SettingsScreen() {
 
   useEffect(() => {
     (async () => {
-      const [im, hv, ai, key, tpl, gp, gu, gt, go, gr, ghu, ghown, ghrepo, glu, glt, glo, glr] =
+      const [im, hv, ai, key, aiUrl, aiMdl, tpl, gp, gu, gt, go, gr, ghu, ghown, ghrepo, glu, glt, glo, glr] =
         await Promise.all([
           SecureStore.getItemAsync(KEYS.INPUT_MODE),
           SecureStore.getItemAsync(KEYS.HOME_VIEW),
           SecureStore.getItemAsync(KEYS.AI_ENABLED),
           SecureStore.getItemAsync(KEYS.AI_KEY),
+          SecureStore.getItemAsync(KEYS.AI_BASE_URL),
+          SecureStore.getItemAsync(KEYS.AI_MODEL),
           SecureStore.getItemAsync(KEYS.MD_TEMPLATE),
           SecureStore.getItemAsync(KEYS.GIT_PROVIDER),
           SecureStore.getItemAsync(KEYS.GITEA_URL),
@@ -121,6 +127,8 @@ export default function SettingsScreen() {
       if (hv) setHomeView(hv as "dashboard" | "capture");
       if (ai) setAiEnabled(ai === "true");
       if (key) setAiKey(key);
+      if (aiUrl) setAiBaseUrl(aiUrl);
+      if (aiMdl) setAiModel(aiMdl);
       if (tpl) setMdTemplate(tpl);
       if (gp) setGitProvider(gp as GitProvider);
       if (gu) setGiteaUrl(gu);
@@ -143,6 +151,8 @@ export default function SettingsScreen() {
       SecureStore.setItemAsync(KEYS.HOME_VIEW, homeView),
       SecureStore.setItemAsync(KEYS.AI_ENABLED, String(aiEnabled)),
       SecureStore.setItemAsync(KEYS.AI_KEY, aiKey),
+      SecureStore.setItemAsync(KEYS.AI_BASE_URL, aiBaseUrl),
+      SecureStore.setItemAsync(KEYS.AI_MODEL, aiModel),
       SecureStore.setItemAsync(KEYS.MD_TEMPLATE, mdTemplate),
       SecureStore.setItemAsync(KEYS.GIT_PROVIDER, gitProvider),
       SecureStore.setItemAsync(KEYS.GITEA_URL, giteaUrl),
@@ -300,20 +310,52 @@ export default function SettingsScreen() {
         ]}
       />
 
-      <Text style={SECTION_TITLE}>AI (optional)</Text>
+      <Text style={SECTION_TITLE}>AI — Root Cause Assistant</Text>
+      <View
+        style={{
+          backgroundColor: Colors.surface,
+          borderRadius: 8,
+          padding: 12,
+          marginBottom: 14,
+          borderLeftWidth: 3,
+          borderLeftColor: Colors.text2,
+        }}
+      >
+        <Text style={{ color: Colors.text2, fontSize: 13, lineHeight: 20 }}>
+          When enabled, a button appears on the capture form to suggest a root cause and fix
+          based on the incident title and symptom. Uses any OpenAI-compatible API —
+          set the base URL below to point at a local Ollama instance or leave empty
+          for OpenAI (api.openai.com).
+        </Text>
+      </View>
       <ToggleRow
         label="Enable AI assistance"
         value={aiEnabled}
         onValueChange={setAiEnabled}
       />
       {aiEnabled && (
-        <Field
-          label="API Key"
-          value={aiKey}
-          onChange={setAiKey}
-          placeholder="sk-..."
-          secure
-        />
+        <>
+          <Field
+            label="API Base URL"
+            value={aiBaseUrl}
+            onChange={setAiBaseUrl}
+            placeholder="http://192.168.x.x:11434/v1  (empty = OpenAI)"
+            url
+          />
+          <Field
+            label="Model"
+            value={aiModel}
+            onChange={setAiModel}
+            placeholder="gpt-4o-mini  or  llama3.2"
+          />
+          <Field
+            label="API Key"
+            value={aiKey}
+            onChange={setAiKey}
+            placeholder="sk-...  (leave empty for Ollama)"
+            secure
+          />
+        </>
       )}
 
       <Text style={SECTION_TITLE}>Git Repository</Text>