fix(imaging): support .hab assets, cache avatars/badges, harden routes

The hotel moved from .nitro to .hab bundles, so the imager must treat .hab
like .nitro and the public avatar endpoints must accept the figure strings
the client sends (including extra trailing segments such as `.0`, which the
old FIGURE_RE rejected with a 400).

- imager-upstream: relax FIGURE_RE, extend parseAvatarQuery test coverage
- api/imaging/avatar + /imaging: shared validation, placeholder and ETag/304
- api/imaging/badge: single-flight upstream fetch and conditional responses
- imager-http/imager-png: strong ETag helpers and APNG passthrough guard
- csp + next/image: unoptimized external images, tightened CSP
- deps: override postcss-selector-parser to ^7.1.6
- also fold in the pending drizzle draft snapshot and stray test cleanup

src/lib/runtime-avatar-route.test.ts

@@ -108,6 +108,28 @@ it("serves a previously rendered avatar from the disk cache without re-fetching"
 	expect(fetcher.mock.calls.length).toBe(callsAfterFirst);
 });
 
+it("revalidates a cached avatar with a 304 when the client already has it", async () => {
+	const fetcher = vi.fn(
+		async () =>
+			new Response(new Uint8Array([1, 2, 3]), {
+				headers: { "content-type": "image/png" },
+			}),
+	);
+	vi.stubGlobal("fetch", fetcher);
+	vi.stubEnv("IMAGER_URL", "https://etag.test/avatarimage");
+	const url = "https://hotel.test/api/imaging/avatar?figure=hd-77-1";
+	const first = await GET(new NextRequest(url));
+	const etag = first.headers.get("etag");
+	expect(etag).toBeTruthy();
+
+	const second = await GET(
+		new NextRequest(url, { headers: { "if-none-match": etag } }),
+	);
+	expect(second.status).toBe(304);
+	expect(second.headers.get("etag")).toBe(etag);
+	expect(second.headers.get("x-imager-source")).toBe("cache");
+});
+
 it("serves a graceful silhouette instead of a broken image when every upstream is down", async () => {
 	const fetcher = vi.fn(
 		async (_input: string | URL) =>