docs: make README generic (remove arrstack/sonarr references)

README.md

@@ -2,8 +2,8 @@
 
 A tiny, stateless Go tool that blocks until a database is ready, then exits `0`.
 It is designed to run as a Kubernetes **initContainer** so an app never starts
-before its database can serve queries. It replaces the hand-written
-`psql`-in-a-shell initContainers we used on the arrstack (sonarr/radarr/prowlarr).
+before its database can serve queries, without hand-writing a `psql`-in-a-shell
+probe in every workload.
 
 Readiness means a trivial liveness query (`SELECT 1`) succeeds under the given
 credentials and database — proving the **server is up, auth works, and the
@@ -46,9 +46,9 @@ is a drop-in replacement anywhere those variables are already set.
 ### Example logs
 
 ```
-12:49:50 waitfordb v0.1.0: waiting for database (driver=postgres addr=db:5432 database=sonarr-main user=sonarr password=*** timeout=5m interval=2s connect_timeout=5s)
-12:49:52 attempt 1: failed to connect to `user=sonarr database=sonarr-main`: dial tcp ... connection refused; retrying in 2s (elapsed 2s/5m)
-12:49:56 database sonarr-main ready after 4.2s (3 attempts)
+12:49:50 waitfordb v0.1.0: waiting for database (driver=postgres addr=db:5432 database=appdb user=appuser password=*** timeout=5m interval=2s connect_timeout=5s)
+12:49:52 attempt 1: failed to connect to `user=appuser database=appdb`: dial tcp ... connection refused; retrying in 2s (elapsed 2s/5m)
+12:49:56 database appdb ready after 4.2s (3 attempts)
 ```
 
 The password is never printed — not in the startup line, not in any error line.
@@ -64,11 +64,11 @@ initContainers:
     image: artifactapi.k8s.syd1.au.unkin.net/docker-internal/waitfordb:latest
     env:
       - name: WAITFORDB_HOST
-        value: arrstack-postgres-rw.arrstack.svc.cluster.local
+        value: postgres-rw.default.svc.cluster.local
       - name: WAITFORDB_PORT
         value: "5432"
       - name: WAITFORDB_DATABASE
-        value: sonarr-main
+        value: appdb
       - name: WAITFORDB_SSLMODE
         value: disable
       - name: WAITFORDB_TIMEOUT
@@ -76,12 +76,12 @@ initContainers:
       - name: WAITFORDB_USER
         valueFrom:
           secretKeyRef:
-            name: sonarr-db
+            name: app-db
             key: username
       - name: WAITFORDB_PASSWORD
         valueFrom:
           secretKeyRef:
-            name: sonarr-db
+            name: app-db
             key: password
     resources:
       requests: