Improve Dynu env handling and document secrets/dynu.env

docs/dynu-dns-inventory.md

@@ -24,6 +24,18 @@ This repository includes a **read-only** Dynu DNS inventory workflow for `lan.dd
 - `DYNU_BASE_URL` (optional, defaults to `https://api.dynu.com`)
 - `DYNU_READ_ONLY` (**must** be `true`)
 
+Recommended local secrets file (not committed): `secrets/dynu.env`
+
+```bash
+DYNU_API_KEY=replace-with-real-api-key
+DYNU_READ_ONLY=true
+DYNU_BASE_URL=https://api.dynu.com
+```
+
+Notes:
+- Keep values unquoted unless required by your shell.
+- `scripts/dynu/build_dns_inventory.sh` will auto-load `secrets/dynu.env` when present.
+
 ## Commands
 
 Run directly:
@@ -36,7 +48,7 @@ DYNU_READ_ONLY=true python3 scripts/dynu/correlate_dynu_with_traefik.py
 Or run the wrapper:
 
 ```bash
-DYNU_READ_ONLY=true DYNU_API_KEY=... scripts/dynu/build_dns_inventory.sh
+scripts/dynu/build_dns_inventory.sh
 ```
 
 ## Artifacts