Fix three crash-looping services: koha-db, homebox, vaultwarden

koha-db: compose used MYSQL_ROOT_PASSWORD/MYSQL_DATABASE/MYSQL_USER/
MYSQL_PASSWORD, but this mariadb:11 image version's entrypoint doesn't
recognize MYSQL_ROOT_PASSWORD as any of its accepted root-password
options at all. Confirmed live: "Database is uninitialized and password
option is not specified" on every start, even though DB_ROOT_PASS was
correctly generated and present in .env the whole time. Switched all
four to their MARIADB_* equivalents.

homebox: a newer homebox release requires HBOX_AUTH_API_KEY_PEPPER (at
least 32 bytes) or the container panics on startup — this installer
never set it. Generate one with generate_password 48 and wire it
through .env + the compose environment block.

vaultwarden: the SMTP setup prompts let you enter a host but leave
"SMTP from address" blank (no default), writing a half-configured state
Vaultwarden refuses to start with ("Both SMTP_HOST and SMTP_FROM need
to be set"). Validate after prompting — if SMTP_HOST is set but
SMTP_FROM came back empty, disable SMTP entirely instead of writing a
config known to crash the container.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01H4k6J1qXXyYxhGEgnJaMvn

services/vaultwarden.sh

@@ -324,6 +324,17 @@ install_vaultwarden() {
         prompt_text "SMTP from address:" "" SMTP_FROM
         prompt_text "SMTP username:" "" SMTP_USER
         prompt_text "SMTP password:" "" SMTP_PASS
+        # Vaultwarden refuses to start at all if SMTP_HOST is set without
+        # SMTP_FROM ("Both SMTP_HOST and SMTP_FROM need to be set") —
+        # confirmed live, crash-loops on every start, not just a warning at
+        # runtime. SMTP_FROM's own prompt has no default, so leaving it
+        # blank here writes exactly that broken half-state. Disable SMTP
+        # entirely rather than let it reach a config known to crash the
+        # container — better than guessing a from-address on your behalf.
+        if [ -z "$SMTP_FROM" ]; then
+            log_warning "No SMTP from address entered — disabling SMTP entirely (Vaultwarden requires both or neither). Re-run this installer to set it up later."
+            SMTP_HOST=""; SMTP_PORT="587"; SMTP_USER=""; SMTP_PASS=""
+        fi
     fi
 
     # Mirrors configure_caddy_for_service's own mode resolution (lib/common.sh):