feat: collections visibility enum (matches recipes) + QR on collection PDF (v0.54.0)

Replaces collections.isPublic (boolean) with collections.visibility
(private/unlisted/public/followers — same enum recipes use). Two-step
migration (0050 adds+backfills, 0051 drops isPublic) since drizzle-kit's
add+drop-in-one-diff rename heuristic needs an interactive prompt we
can't satisfy here.

New collectionVisibleToViewer(viewerId) in lib/visibility.ts mirrors the
existing recipe helper (author always sees own; public/unlisted visible
to anyone; followers-only via the same user_follows EXISTS pattern) —
used by the collection detail page, its print view, fork, and favorite,
replacing their old `or(isPublic, own)` checks.

Create/edit collection dialogs get the same 4-option visibility select
as the recipe form instead of a public/private checkbox.

Collection PDF export now generates a QR code (qrcode, same as the
recipe PDF) linking to /collections/{id}, shown only when visibility is
public/unlisted — same "would an anonymous scanner actually resolve
this" rule as the recipe QR.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

apps/web/lib/changelog.ts

@@ -1,5 +1,5 @@
 // Mirrors CHANGELOG.md at the repo root — update both together.
-export const APP_VERSION = "0.53.1";
+export const APP_VERSION = "0.54.0";
 
 export type ChangelogEntry = {
   version: string;
@@ -11,6 +11,14 @@ export type ChangelogEntry = {
 };
 
 export const CHANGELOG: ChangelogEntry[] = [
+  {
+    version: "0.54.0",
+    date: "2026-07-19 17:05",
+    added: [
+      "Collections now have the same visibility options as recipes — private, followers-only, unlisted, or public — replacing the old public/private toggle. Fork, favorite, and viewing a collection all respect the new followers-only option the same way recipes do.",
+      "Collection PDF exports now include a QR code linking back to the collection, same as recipe PDFs (only for unlisted/public collections, matching the recipe QR's own rule about what an anonymous scanner could actually open).",
+    ],
+  },
   {
     version: "0.53.1",
     date: "2026-07-19 16:10",