feat: apply Charbon·Lime design system, add gear icon, multi-provider git settings

- Replace app icon with new Charbon·Lime brand assets (icon.png + adaptive-icon.png)
- Apply design tokens to theme.ts: bg #1B2433, primary/success #88D656 (lime), text1 #EEF2F5 (cream)
- Add ⚙ gear button (lime) in HomeScreen header → navigates to /settings
- Expand settings: git provider selector (Gitea / GitHub / GitLab) with per-provider fields
- Add lib/git.ts: unified pushIncidentToGit() for Gitea, GitHub (PUT), and GitLab APIs
- Update incident detail screen to use lib/git.ts and dynamic provider routing

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

app/incident/[id].tsx

@@ -12,7 +12,8 @@ import * as Clipboard from "expo-clipboard";
 import * as SecureStore from "expo-secure-store";
 import { getIncidentById, updateIncident } from "@/lib/db";
 import { renderMarkdown } from "@/lib/markdown";
-import { pushIncidentToGitea } from "@/lib/gitea";
+import { pushIncidentToGit } from "@/lib/git";
+import type { GitProvider } from "@/lib/git";
 import type { Incident } from "@/types/incident";
 import { Colors } from "@/constants/theme";
 
@@ -59,28 +60,62 @@ export default function IncidentDetailScreen() {
     setIncident({ ...incident, status: "resolved" });
   }
 
-  async function handleGiteaPush() {
+  async function handleGitPush() {
     if (!incident) return;
-    const [url, token, owner, repo, template] = await Promise.all([
-      SecureStore.getItemAsync("gitea_url"),
-      SecureStore.getItemAsync("gitea_token"),
-      SecureStore.getItemAsync("gitea_owner"),
-      SecureStore.getItemAsync("gitea_repo"),
-      SecureStore.getItemAsync("md_template"),
-    ]);
-    if (!url || !token || !owner || !repo) {
-      Alert.alert("Gitea not configured", "Set up Gitea in Settings first.");
+    const [provider, template, giteaUrl, giteaToken, giteaOwner, giteaRepo, githubToken, githubOwner, githubRepo, gitlabUrl, gitlabToken, gitlabOwner, gitlabRepo] =
+      await Promise.all([
+        SecureStore.getItemAsync("git_provider"),
+        SecureStore.getItemAsync("md_template"),
+        SecureStore.getItemAsync("gitea_url"),
+        SecureStore.getItemAsync("gitea_token"),
+        SecureStore.getItemAsync("gitea_owner"),
+        SecureStore.getItemAsync("gitea_repo"),
+        SecureStore.getItemAsync("github_token"),
+        SecureStore.getItemAsync("github_owner"),
+        SecureStore.getItemAsync("github_repo"),
+        SecureStore.getItemAsync("gitlab_url"),
+        SecureStore.getItemAsync("gitlab_token"),
+        SecureStore.getItemAsync("gitlab_owner"),
+        SecureStore.getItemAsync("gitlab_repo"),
+      ]);
+
+    const p = (provider ?? "gitea") as GitProvider;
+
+    let url: string | undefined;
+    let token: string | null;
+    let owner: string | null;
+    let repo: string | null;
+
+    if (p === "gitea") {
+      url = giteaUrl ?? undefined;
+      token = giteaToken;
+      owner = giteaOwner;
+      repo = giteaRepo;
+    } else if (p === "github") {
+      token = githubToken;
+      owner = githubOwner;
+      repo = githubRepo;
+    } else {
+      url = gitlabUrl ?? undefined;
+      token = gitlabToken;
+      owner = gitlabOwner;
+      repo = gitlabRepo;
+    }
+
+    if (!token || !owner || !repo) {
+      Alert.alert("Git not configured", `Set up ${p.charAt(0).toUpperCase() + p.slice(1)} in Settings first.`);
       return;
     }
+
     setPushing(true);
-    const result = await pushIncidentToGitea(
+    const result = await pushIncidentToGit(
       incident,
-      { url, token, owner, repo },
+      { provider: p, url, token, owner, repo },
       template ?? undefined
     );
     setPushing(false);
     if (result.success) {
-      Alert.alert("Pushed", result.url ? `${result.url}` : "Push successful.");
+      Alert.alert("Pushed", result.url ?? "Push successful.");
     } else {
       Alert.alert("Push failed", result.error ?? "Unknown error");
     }
@@ -117,7 +152,7 @@ export default function IncidentDetailScreen() {
         <View
           style={{
             backgroundColor:
-              incident.status === "open" ? "#f59e0b20" : "#22c55e20",
+              incident.status === "open" ? "#f59e0b20" : "#88D65620",
             borderRadius: 6,
             paddingHorizontal: 10,
             paddingVertical: 4,
@@ -188,7 +223,7 @@ export default function IncidentDetailScreen() {
           <Pressable
             onPress={handleResolve}
             style={{
-              backgroundColor: "#22c55e20",
+              backgroundColor: "#88D65620",
               borderWidth: 1,
               borderColor: Colors.success,
               borderRadius: 10,
@@ -219,7 +254,7 @@ export default function IncidentDetailScreen() {
         </Pressable>
 
         <Pressable
-          onPress={handleGiteaPush}
+          onPress={handleGitPush}
           disabled={pushing}
           style={{
             backgroundColor: pushing ? Colors.surface2 : Colors.surface,
@@ -237,7 +272,7 @@ export default function IncidentDetailScreen() {
               fontSize: 15,
             }}
           >
-            {pushing ? "Pushing…" : "Push to Gitea"}
+            {pushing ? "Pushing…" : "Push to Git"}
           </Text>
         </Pressable>