Docker: persist API Server state, wire up OCPP, drop legacy env names

Audited every Dockerfile, compose file and .env.example against the code
they deploy. Four things had drifted:

Persistence. The API Server writes plugins.json and rewrites .env (the
panel's retarget-PocketBase flow) relative to its working directory,
which was a root-owned /app while the process runs as the app user - so
both writes failed, and no volume was declared to keep them anyway. The
binary moves to /usr/local/bin and the working directory becomes a /data
volume owned by app. The AIO image gets the same via directory=/data on
its supervisord program.

OCPP. Charger control was undeployable: OCPP_REQUIRE_TLS defaults to true
and appeared in no Docker file, so a charger dialling the plain-HTTP
/ocpp/{serial} was rejected with nothing explaining why. Both OCPP vars
are now threaded through the compose files and env examples, with the
reasoning (the per-charger control token rides in a Basic-auth header).

CORS. API Server/docker-compose.yml defaulted to localhost:5173, the Vite
dev port, where every other file uses 8090.

Env names. .env.example has called PB_URL/PB_ADMIN_*/PORT legacy for a
while, but the Docker layer still used them. Container-side names are now
POCKETBASE_*/API_ADDR; the .env keys operators set stay PB_ADMIN_* so
existing .env files keep working.

Left alone deliberately: alpine:latest stays unpinned (cannot verify
current tags or test the build from here), and the golang/node bases
already match go.mod and Vite 8's floor.

Validated as YAML only - there is no Docker CLI on this machine, so no
image was built and the /data ownership fix follows standard volume
semantics rather than an observed run.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

API Server/.env.example

@@ -31,8 +31,23 @@ WEBAPP_URL=http://localhost:8090
 AUTH_USERS_COLLECTION=users
 
 # Local JSON store for plugin enable-state + config (default: plugins.json).
+# Relative paths resolve against the working directory, so in Docker this points
+# at the mounted volume (see the Dockerfile) rather than the image layer.
 PLUGINS_FILE=plugins.json
 
+# --- EV charging control (Anker Solix, OCPP) ---------------------------------
+# Only relevant when a charger is set to own/proxy control mode. The charger
+# dials in to /ocpp/{serial} on this server, authenticating with OCPP Basic auth
+# (serial + per-charger control token). A plaintext ws:// would carry that token
+# in the clear, so connections that did not arrive over TLS are rejected —
+# disable only for local dev on a trusted network.
+OCPP_REQUIRE_TLS=true
+
+# The canonical ws(s):// base an operator points the charger at. Set this when
+# the server sits behind a reverse proxy, where deriving the URL from request
+# headers is unreliable. Empty = derive it.
+OCPP_PUBLIC_URL=
+
 # --- Legacy names -----------------------------------------------------------
 # PB_URL, PB_ADMIN_EMAIL, PB_ADMIN_PASSWORD, PORT and CORS_ORIGINS are still
 # honoured for older deployments; the POCKETBASE_*/API_ADDR names above win when