Add env-driven SMTP and app identity settings for PocketBase

- pb_hooks/main.pb.js: bootstrap hook applying SMTP + meta settings from
  env vars on every boot (mail disabled when SMTP_HOST is unset)
- docker-compose.yml: expose SMTP_* / PB_APP_URL on the pocketbase service
- pocketbase/Dockerfile: bundle pb_hooks
- README: document the new variables

docker-compose.yml

@@ -11,6 +11,17 @@ services:
             # Optional: create/update the admin account on boot (min 8 chars)
             PB_SUPERUSER_EMAIL: ${PB_SUPERUSER_EMAIL:-}
             PB_SUPERUSER_PASSWORD: ${PB_SUPERUSER_PASSWORD:-}
+            # Optional: app URL used in transactional emails (reset links...)
+            PB_APP_URL: ${PB_APP_URL:-}
+            # Optional: SMTP for transactional emails. If SMTP_HOST is empty,
+            # mail stays disabled (the rest is ignored).
+            SMTP_HOST: ${SMTP_HOST:-}
+            SMTP_PORT: ${SMTP_PORT:-587}
+            SMTP_USERNAME: ${SMTP_USERNAME:-}
+            SMTP_PASSWORD: ${SMTP_PASSWORD:-}
+            SMTP_TLS: ${SMTP_TLS:-true}
+            SMTP_SENDER_NAME: ${SMTP_SENDER_NAME:-PokeShare}
+            SMTP_SENDER_ADDRESS: ${SMTP_SENDER_ADDRESS:-}
         volumes:
             - pb_data:/pb/pb_data