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/tests/infra/docker-compose.yaml

@@ -0,0 +1,27 @@
+version: '3.8'
+services:
+  # An ephermerally-stored postgres database for single-use test runs
+  db_test: &db_test
+    image: postgres:14.11-alpine
+    environment:
+      - POSTGRES_USER=pg
+      - POSTGRES_PASSWORD=password
+    ports:
+      - '5433:5432'
+    # Healthcheck ensures db is queryable when `docker-compose up --wait` completes
+    healthcheck:
+      test: 'pg_isready -U pg'
+      interval: 500ms
+      timeout: 10s
+      retries: 20
+  # A persistently-stored postgres database
+  db:
+    <<: *db_test
+    ports:
+      - '5432:5432'
+    healthcheck:
+      disable: true
+    volumes:
+      - link_db:/var/lib/postgresql/data
+volumes:
+  link_db: