docs: 'just seed' recipe + README seed step (#14)

README.md

@@ -49,7 +49,14 @@ BOOTSTRAP_PASSWORD=changeme123 cargo run -p server -- create-user --email you@ex
 ```
 Roles are `admin` or `editor`.
 
-### 5. Run the web frontend
+### 5. Seed the baseline cataloguing fields (idempotent)
+```bash
+just seed            # or: cargo run -p server -- seed
+```
+Populates the baseline Spectrum cataloguing vocabularies and field definitions. Safe to
+re-run — the seed is idempotent.
+
+### 6. Run the web frontend
 The API server serves JSON only; in development the SPA is served by Vite, which proxies
 `/api` to `:8080`:
 ```bash

justfile

@@ -4,6 +4,10 @@ set dotenv-load
 run:
     cargo run -p server
 
+# Seed the baseline Spectrum cataloguing vocabularies + field definitions (idempotent)
+seed:
+    cargo run -p server -- seed
+
 # Run the full test suite via cargo-nextest (per-test isolation, live output,
 # hang timeouts). nextest does not run doctests, so they run separately.
 test: