feat(web): show deployed commit SHA in landing footer

apps/web/src/components/landing/footer.tsx

@@ -141,8 +141,18 @@ export function Footer() {
 						© {new Date().getFullYear()} Stackpanel · MIT licensed · Built on
 						Nix, devenv, Caddy, SOPS, and process-compose
 					</p>
-					<p className="text-muted-foreground text-xs">
-						Not affiliated with NixOS, devenv, or Cloudflare.
+					<p className="flex items-center gap-2 text-muted-foreground text-xs">
+						<span>Not affiliated with NixOS, devenv, or Cloudflare.</span>
+						<span aria-hidden>·</span>
+						<a
+							className="font-mono transition-colors hover:text-foreground"
+							href={`https://github.com/darkmatter/stackpanel/commit/${__COMMIT_SHA__}`}
+							rel="noopener noreferrer"
+							target="_blank"
+							title="Deployed commit"
+						>
+							{__COMMIT_SHA__}
+						</a>
 					</p>
 				</div>
 			</div>

apps/web/src/types/build-info.d.ts

@@ -0,0 +1 @@
+declare const __COMMIT_SHA__: string;

apps/web/vite.config.ts

@@ -2,6 +2,7 @@ import tailwindcss from "@tailwindcss/vite";
 import { tanstackStart } from "@tanstack/react-start/plugin/vite";
 import viteReact from "@vitejs/plugin-react";
 // import alchemy from "alchemy/cloudflare/tanstack-start";
+import { execSync } from "node:child_process";
 import type { Plugin } from "vite";
 import { defineConfig } from "vite";
 import tsconfigPaths from "vite-tsconfig-paths";
@@ -30,7 +31,20 @@ function patchImportMetaUrl(): Plugin {
 
 const docsProxyUrl = process.env.DOCS_PROXY_URL || "http://localhost:4000";
 
+const commitSha = (() => {
+  const fromCi = process.env.GITHUB_SHA;
+  if (fromCi) return fromCi.slice(0, 7);
+  try {
+    return execSync("git rev-parse --short HEAD", { encoding: "utf8" }).trim();
+  } catch {
+    return "unknown";
+  }
+})();
+
 export default defineConfig({
+  define: {
+    __COMMIT_SHA__: JSON.stringify(commitSha),
+  },
   plugins: [
     tsconfigPaths({
       skip: (dir) => dir === ".worktrees" || dir === ".stack",