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/imager-png.test.ts

@@ -0,0 +1,62 @@
+import { describe, expect, it } from "vitest";
+import { isAnimatedPng } from "./imager-png";
+
+function png(chunks: Array<{ type: string; data?: number[] }>): Uint8Array {
+	const bytes = [0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a];
+	for (const chunk of chunks) {
+		const data = chunk.data ?? [];
+		const len = data.length;
+		bytes.push(
+			(len >>> 24) & 0xff,
+			(len >>> 16) & 0xff,
+			(len >>> 8) & 0xff,
+			len & 0xff,
+			...chunk.type.split("").map((c) => c.charCodeAt(0)),
+			...data,
+			0,
+			0,
+			0,
+			0,
+		);
+	}
+	return new Uint8Array(bytes);
+}
+
+describe("isAnimatedPng", () => {
+	it("returns false for non-PNG input", () => {
+		expect(isAnimatedPng(new Uint8Array([1, 2, 3]))).toBe(false);
+		expect(isAnimatedPng(new Uint8Array())).toBe(false);
+	});
+
+	it("returns false for a plain PNG", () => {
+		const plain = png([{ type: "IHDR" }, { type: "IDAT" }, { type: "IEND" }]);
+		expect(isAnimatedPng(plain)).toBe(false);
+	});
+
+	it("returns true when an acTL chunk precedes IDAT", () => {
+		const anim = png([
+			{ type: "IHDR" },
+			{ type: "acTL", data: [0, 16, 0, 0] },
+			{ type: "IDAT" },
+			{ type: "IEND" },
+		]);
+		expect(isAnimatedPng(anim)).toBe(true);
+	});
+
+	it("ignores an acTL chunk that appears after IDAT", () => {
+		const late = png([
+			{ type: "IHDR" },
+			{ type: "IDAT" },
+			{ type: "acTL", data: [0, 16, 0, 0] },
+		]);
+		expect(isAnimatedPng(late)).toBe(false);
+	});
+
+	it("does not loop forever on a corrupt chunk length", () => {
+		const corrupt = new Uint8Array([
+			0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a, 0xff, 0xff, 0xff, 0xff,
+			0x49, 0x48, 0x44, 0x52,
+		]);
+		expect(isAnimatedPng(corrupt)).toBe(false);
+	});
+});