Canadian cities labeler over Bluesky DMs

Users DM @cities.pds.cosocial.ca their city and get a signed account label.
Serves com.atproto.label.queryLabels and subscribeLabels, built on jacquard.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.env.example

@@ -0,0 +1,9 @@
+LABELER_HANDLE=cities.pds.cosocial.ca
+# Settings → Privacy and security → App passwords, with "Allow access to your direct messages"
+LABELER_APP_PASSWORD=
+# from `cargo run --bin keygen`
+SIGNING_KEY_HEX=
+# PDS_URL=https://pds.cosocial.ca
+# PORT=4100
+# DB_PATH=labeler.sqlite
+# CITIES_PATH=data/cities.json