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>

lib/git.ts

@@ -0,0 +1,174 @@
+import { incidentToFilename, renderMarkdown } from "./markdown";
+import type { Incident } from "@/types/incident";
+
+export type GitProvider = "gitea" | "github" | "gitlab";
+
+export interface GitConfig {
+  provider: GitProvider;
+  url?: string;   // required for gitea and self-hosted gitlab
+  token: string;
+  owner: string;
+  repo: string;
+}
+
+export interface PushResult {
+  success: boolean;
+  url?: string;
+  error?: string;
+}
+
+export async function pushIncidentToGit(
+  incident: Incident,
+  config: GitConfig,
+  markdownTemplate?: string
+): Promise<PushResult> {
+  switch (config.provider) {
+    case "gitea":
+      return pushGitea(incident, config, markdownTemplate);
+    case "github":
+      return pushGitHub(incident, config, markdownTemplate);
+    case "gitlab":
+      return pushGitLab(incident, config, markdownTemplate);
+  }
+}
+
+async function pushGitea(
+  incident: Incident,
+  config: GitConfig,
+  markdownTemplate?: string
+): Promise<PushResult> {
+  const filepath = incidentToFilename(incident);
+  const content = renderMarkdown(incident, markdownTemplate);
+  const base64Content = btoa(unescape(encodeURIComponent(content)));
+  const apiBase = (config.url ?? "").replace(/\/$/, "");
+  const endpoint = `${apiBase}/api/v1/repos/${config.owner}/${config.repo}/contents/${filepath}`;
+
+  try {
+    const existing = await fetch(endpoint, {
+      headers: { Authorization: `Bearer ${config.token}` },
+    });
+    let sha: string | undefined;
+    if (existing.ok) {
+      const data = await existing.json() as { sha?: string };
+      sha = data.sha;
+    }
+
+    const body: Record<string, string> = {
+      message: `incident: ${incident.title}`,
+      content: base64Content,
+    };
+    if (sha) body.sha = sha;
+
+    const res = await fetch(endpoint, {
+      method: "POST",
+      headers: {
+        Authorization: `Bearer ${config.token}`,
+        "Content-Type": "application/json",
+      },
+      body: JSON.stringify(body),
+    });
+
+    if (!res.ok) {
+      return { success: false, error: `HTTP ${res.status}: ${await res.text()}` };
+    }
+    const data = await res.json() as { content?: { html_url?: string } };
+    return { success: true, url: data.content?.html_url };
+  } catch (e) {
+    return { success: false, error: e instanceof Error ? e.message : String(e) };
+  }
+}
+
+async function pushGitHub(
+  incident: Incident,
+  config: GitConfig,
+  markdownTemplate?: string
+): Promise<PushResult> {
+  const filepath = incidentToFilename(incident);
+  const content = renderMarkdown(incident, markdownTemplate);
+  const base64Content = btoa(unescape(encodeURIComponent(content)));
+  const endpoint = `https://api.github.com/repos/${config.owner}/${config.repo}/contents/${filepath}`;
+
+  try {
+    const existing = await fetch(endpoint, {
+      headers: {
+        Authorization: `Bearer ${config.token}`,
+        Accept: "application/vnd.github+json",
+      },
+    });
+    let sha: string | undefined;
+    if (existing.ok) {
+      const data = await existing.json() as { sha?: string };
+      sha = data.sha;
+    }
+
+    const body: Record<string, string> = {
+      message: `incident: ${incident.title}`,
+      content: base64Content,
+    };
+    if (sha) body.sha = sha;
+
+    const res = await fetch(endpoint, {
+      method: "PUT",
+      headers: {
+        Authorization: `Bearer ${config.token}`,
+        Accept: "application/vnd.github+json",
+        "Content-Type": "application/json",
+      },
+      body: JSON.stringify(body),
+    });
+
+    if (!res.ok) {
+      return { success: false, error: `HTTP ${res.status}: ${await res.text()}` };
+    }
+    const data = await res.json() as { content?: { html_url?: string } };
+    return { success: true, url: data.content?.html_url };
+  } catch (e) {
+    return { success: false, error: e instanceof Error ? e.message : String(e) };
+  }
+}
+
+async function pushGitLab(
+  incident: Incident,
+  config: GitConfig,
+  markdownTemplate?: string
+): Promise<PushResult> {
+  const filepath = incidentToFilename(incident);
+  const content = renderMarkdown(incident, markdownTemplate);
+  const base64Content = btoa(unescape(encodeURIComponent(content)));
+  const apiBase = (config.url ?? "https://gitlab.com").replace(/\/$/, "");
+  const projectId = encodeURIComponent(`${config.owner}/${config.repo}`);
+  const encodedPath = encodeURIComponent(filepath);
+  const endpoint = `${apiBase}/api/v4/projects/${projectId}/repository/files/${encodedPath}`;
+
+  try {
+    const existing = await fetch(`${endpoint}?ref=HEAD`, {
+      headers: { "PRIVATE-TOKEN": config.token },
+    });
+    const method = existing.ok ? "PUT" : "POST";
+
+    const res = await fetch(endpoint, {
+      method,
+      headers: {
+        "PRIVATE-TOKEN": config.token,
+        "Content-Type": "application/json",
+      },
+      body: JSON.stringify({
+        branch: "main",
+        content: base64Content,
+        encoding: "base64",
+        commit_message: `incident: ${incident.title}`,
+      }),
+    });
+
+    if (!res.ok) {
+      return { success: false, error: `HTTP ${res.status}: ${await res.text()}` };
+    }
+    const data = await res.json() as { file_path?: string };
+    const webUrl = data.file_path
+      ? `${apiBase}/${config.owner}/${config.repo}/-/blob/main/${data.file_path}`
+      : undefined;
+    return { success: true, url: webUrl };
+  } catch (e) {
+    return { success: false, error: e instanceof Error ? e.message : String(e) };
+  }
+}