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-upstream.ts

@@ -8,7 +8,12 @@ import {
 } from "@/lib/imager-cache";
 import { resolveImagerBase } from "@/lib/runtime-asset-config";
 
-export const FIGURE_RE = /^[a-z]{2}-\d+(?:-\d+)*(?:\.[a-z]{2}-\d+(?:-\d+)*)*$/i;
+// The client's figure strings are passed straight through to the imager, which
+// is the authority on what it can draw. Only the first segment is required to
+// look like a real part (`hd-180`); the rest is deliberately loose because some
+// clients append extra segments (e.g. a trailing `.0`) that the renderer still
+// accepts. Over-strict validation here turned valid avatars into 400s.
+export const FIGURE_RE = /^[a-z]{2}-\d+(?:[.-][a-z0-9]+)*$/i;
 export const FIGURE_MAX_LEN = 512;
 export const FIGURE_MAX_PARTS = 24;