fix: replace generic exit 1 with specific exit codes in ct/ and install/ scripts (#12475)

Part of #12467 — scripts only (no framework changes).

New exit codes 250-254 registered in api.func and error_handler.func:
- 250: App download failed or version not determined
- 251: App file extraction failed (corrupt/incomplete archive)
- 252: App required file or resource not found
- 253: App data migration required — update aborted
- 254: App user declined prompt or input timed out

Existing codes reused where applicable:
- 10: privileged/Docker required (unifi-os-server)
- 64: invalid user input (postgresql, tomcat)
- 71: system error (pulse useradd)
- 150: service failed to start (docker, npmplus)
- 153: build failed (booklore)
- 233: app not installed (evcc, endurain, grafana, loki, itsm-ng)
- 236: hardware not detected (unifi-os-server /dev/net/tun)
- 238: OS not supported (frigate)

ct/alpine-komodo.sh

@@ -39,7 +39,7 @@ function update_script() {
     COMPOSE_FILE=$(find /opt/komodo -maxdepth 1 -type f -name '*.compose.yaml' ! -name 'compose.env' | head -n1)
     if [[ -z "$COMPOSE_FILE" ]]; then
       msg_error "No valid compose file found in /opt/komodo!"
-      exit 1
+      exit 252
     fi
     $STD docker compose -p komodo -f "$COMPOSE_FILE" --env-file /opt/komodo/compose.env pull
     $STD docker compose -p komodo -f "$COMPOSE_FILE" --env-file /opt/komodo/compose.env up -d