Seed fresh local DB from .dev production dump automatically

README.md

@@ -28,11 +28,14 @@ tables byte-for-byte (verified by diffing `mariadb-dump --no-data` against the p
 its creates are guarded with `Schema::hasTable`, so running `migrate` on production only
 records it. Add new migrations in the backend for any schema change; the site app has none.
 
-To work with real content, load a production dump (drops and recreates the local DB):
+Real content: drop the production export at `.dev/greaterc_db2024.sql` (or the `.sql.zip`
+phpMyAdmin produced — it's unzipped on demand; both are git-ignored). A fresh DB seeds
+itself from it on first `nix run`; existing data is never overwritten on restart.
 
 ```sh
-nix run . -- db import .dev/greaterc_db2024.sql   # phpMyAdmin export, kept out of git
-nix run . -- db reset                             # back to empty schema
+nix run . -- db reset                 # wipe + reseed from the dump (or empty schema if none)
+nix run . -- db import other.sql      # load a different dump
+DEV_DB_DUMP=/path/to/x.sql nix run    # use a dump elsewhere
 ```
 
 `nix run . -- <cmd>` forwards to the `dev` script; `nix develop` drops you into a shell with