refactor(packaging): split into dispatch/dispatch-systemd/dispatch-s6, separate dispatch-electron, add bun-based frontend serve

PKGBUILD is now a split package producing three .pkg.tar.zst files in one
makepkg run:
  - dispatch          base application files (/opt/dispatch), CLI wrappers
                       (dispatch-api, dispatch-frontend), env configs
                       (/etc/dispatch/dispatch-api.conf,
                        /etc/dispatch/dispatch-frontend.conf)
  - dispatch-systemd  systemd user units for dispatch-api + dispatch-frontend
                       (conflicts with dispatch-s6)
  - dispatch-s6       s6-rc service pipelines (-srv + -log) for both services
                       (conflicts with dispatch-systemd)

The Electron desktop wrapper moved to its own self-contained PKGBUILD at
packaging/electron/, producing dispatch-electron. It bundles its own copy of
the frontend dist + electron entry points under /opt/dispatch-electron and
does not depend on the base dispatch package, so users can install it
standalone and point VITE_API_URL at any backend at build time.

Files under packaging/ are now read directly from ${_projectdir}/packaging/
rather than via source=(); the two s6 service dirs share basenames (run,
type) which would collide inside ${srcdir}.

New frontend static server: packages/frontend/serve.ts uses Bun's built-in
HTTP server (no extra runtime deps) with SPA fallback to index.html and
path-traversal protection. PORT/HOST/DIST_DIR overridable via env. Exposed
as 'bun run --cwd packages/frontend serve' and via /usr/bin/dispatch-frontend.

Build scripts:
  - bin/build-pkg            now prints the freshest built packages
  - bin/install-pkg          installs dispatch + dispatch-systemd by default;
                              accepts package names or --all; searches both
                              packaging/ and packaging/electron/
  - bin/build-pkg-electron   new, builds the electron split
  - bin/build-pkg-windows    replaces bin/windows-pkg; drops the hard-coded
                              WSL copy step, just prints the win-unpacked path

.gitignore extended to cover packaging/*.tar.zst and packaging/electron/{src,pkg,*.pkg.tar.zst,*.tar.zst}.

2 files changed, 67 insertions, 0 deletions

diff --git a/packages/frontend/package.json b/packages/frontend/package.json
index 453df07..1d11524 100644
--- a/packages/frontend/package.json
+++ b/packages/frontend/package.json
@@ -8,6 +8,7 @@
 		"dev": "vite",
 		"build": "vite build",
 		"preview": "vite preview",
+		"serve": "bun serve.ts",
 		"test": "vitest run",
 		"test:watch": "vitest",
 		"typecheck": "svelte-check --tsconfig ./tsconfig.json",
diff --git a/packages/frontend/serve.ts b/packages/frontend/serve.ts
new file mode 100644
index 0000000..75b0a9f
--- /dev/null
+++ b/packages/frontend/serve.ts
@@ -0,0 +1,66 @@
+// Static file server for the built frontend (packages/frontend/dist).
+// Uses Bun's built-in HTTP server — no extra runtime dependencies.
+//
+// Environment variables:
+//   PORT     — port to listen on (default: 18391)
+//   HOST     — interface to bind to (default: 0.0.0.0)
+//   DIST_DIR — absolute path to the static assets directory
+//              (default: <this-file's-dir>/dist)
+//
+// SPA fallback: requests that don't match a file on disk fall back to
+// index.html so client-side routing works.
+
+import { existsSync, statSync } from "node:fs";
+import { join, normalize, resolve } from "node:path";
+import { fileURLToPath } from "node:url";
+
+const moduleDir = (() => {
+	try {
+		// @ts-expect-error — Bun provides import.meta.dir
+		return import.meta.dir as string;
+	} catch {
+		return resolve(fileURLToPath(import.meta.url), "..");
+	}
+})();
+
+const port = Number(process.env.PORT) || 18391;
+const host = process.env.HOST || "0.0.0.0";
+const distDir = resolve(process.env.DIST_DIR || join(moduleDir, "dist"));
+
+if (!existsSync(distDir) || !statSync(distDir).isDirectory()) {
+	console.error(`[dispatch-frontend] dist directory not found: ${distDir}`);
+	console.error("[dispatch-frontend] Build the frontend first (bun run --cwd packages/frontend build)");
+	process.exit(1);
+}
+
+const indexPath = join(distDir, "index.html");
+
+function safeResolve(urlPath: string): string | null {
+	// Normalize and prevent path-traversal outside distDir.
+	const decoded = decodeURIComponent(urlPath);
+	const candidate = resolve(distDir, "." + normalize(decoded));
+	if (!candidate.startsWith(distDir)) return null;
+	return candidate;
+}
+
+Bun.serve({
+	port,
+	hostname: host,
+	async fetch(req) {
+		const url = new URL(req.url);
+		let pathname = url.pathname;
+		if (pathname === "/" || pathname === "") pathname = "/index.html";
+
+		const resolved = safeResolve(pathname);
+		if (resolved && existsSync(resolved) && statSync(resolved).isFile()) {
+			return new Response(Bun.file(resolved));
+		}
+
+		// SPA fallback — serve index.html for unknown routes
+		return new Response(Bun.file(indexPath), {
+			headers: { "content-type": "text/html; charset=utf-8" },
+		});
+	},
+});
+
+console.log(`[dispatch-frontend] serving ${distDir} on http://${host}:${port}`);