Bsky short link service (#4542)

* bskylink: scaffold service w/ initial config and schema

* bskylink: implement link creation and redirects

* bskylink: tidy

* bskylink: tests

* bskylink: tidy, add error handler

* bskylink: add dockerfile

* bskylink: add build

* bskylink: fix some express plumbing

* bskyweb: proxy fallthrough routes to link service redirects

* bskyweb: build w/ link proxy

* Add AASA to bskylink (#4588)

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Co-authored-by: Hailey <me@haileyok.com>

bskylink/src/routes/index.ts

@@ -0,0 +1,17 @@
+import {Express} from 'express'
+
+import {AppContext} from '../context.js'
+import {default as create} from './create.js'
+import {default as health} from './health.js'
+import {default as redirect} from './redirect.js'
+import {default as siteAssociation} from './siteAssociation.js'
+
+export * from './util.js'
+
+export default function (ctx: AppContext, app: Express) {
+  app = health(ctx, app) // GET /_health
+  app = siteAssociation(ctx, app) // GET /.well-known/apple-app-site-association
+  app = create(ctx, app) // POST /link
+  app = redirect(ctx, app) // GET /:linkId (should go last due to permissive matching)
+  return app
+}