feat(docker): add configurable path for vecna.json

* set default config path to /config
* update docker-compose example for config usage
* modify config resolution to include /config directory

docker-compose.example.yml

@@ -10,8 +10,8 @@ services:
       - vecna_config:/config
     environment:
       VECNA_SERVER_PORT: 8080
+      # VECNA_CONFIG: /config/vecna.json   # default; override to use a different path
       # VECNA_SERVER_API_KEYS: sk-vecna-abc123,sk-vecna-def456
-    command: ["serve", "--config", "/config/vecna.json"]
     restart: unless-stopped
     depends_on:
       ollama:
@@ -64,18 +64,18 @@ volumes:
 #
 # Run the interactive onboard wizard (writes config into the vecna_config volume):
 #
-#   docker compose run --rm -it vecna onboard --config /config/vecna.json
+#   docker compose run --rm -it vecna onboard
 #
 # The wizard will discover the ollama service on the Docker network at
 # http://ollama:11434 (select it from the list or enter the URL manually).
 #
 # Test all configured endpoints after onboarding:
 #
-#   docker compose run --rm vecna test --config /config/vecna.json
+#   docker compose run --rm vecna test
 #
 # Remove broken endpoints automatically:
 #
-#   docker compose run --rm vecna test --config /config/vecna.json --remove-broken
+#   docker compose run --rm vecna test --remove-broken
 #
 # Open the config in a shell editor (requires the alpine image):
 #