fix(dankserver): copyparty ac edition takes accounts and volumes as argv flags

Ground truth from the image itself: python3 -m copyparty --help-accounts shows
-a takes USER:PASS and -v takes SRC:DST:PERMS:FLAGS — the COPAY_PASS/COPAY_MODE
envs this compose carried are not consumed by this image at all (zero COPAY_
references in the package). With no accounts and no volumes configured, the ac
edition serves its cwd read/write for everyone: the stack was running an
unauthenticated world-writable share of the 91T array. Now: admin account dank
with the A flag on volume /w; anonymous gets nothing.

dankserver/compose.yaml

@@ -77,9 +77,7 @@ services:
     image: ghcr.io/9001/copyparty-ac:latest
     container_name: copyparty
     restart: unless-stopped
-    environment:
-      COPAY_PASS: "${COPAY_PASS}"
-      COPAY_MODE: rw
+    command: ["-a", "dank:${COPAY_PASS}", "-v", "/w::A"]
     ports:
       - "3923:3923"
     volumes: