fix(rn): remove Metro shutdown handlers to respect dev mode

Metro shutdown handlers in process-compose ran unconditionally on exit,
overriding the cleanup block's pure-mode check. Remove shutdown handlers
and let the cleanup block control Metro lifecycle based on DEVBOX_PURE_SHELL.

This keeps Metro running in dev mode for iteration.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: abueide

examples/react-native/tests/test-suite-all-e2e.yaml

@@ -122,10 +122,6 @@ processes:
         condition: process_completed_successfully
     availability:
       restart: "no"
-    shutdown:
-      command: "metro.sh stop all || true"
-      signal: 15
-      timeout_seconds: 5
     readiness_probe:
       exec:
         command: "metro.sh health all ios"

examples/react-native/tests/test-suite-android-e2e.yaml

@@ -76,10 +76,6 @@ processes:
         condition: process_completed_successfully
     availability:
       restart: "no"
-    shutdown:
-      command: "metro.sh stop android || true"
-      signal: 15
-      timeout_seconds: 5
     readiness_probe:
       exec:
         command: "metro.sh health android android"

examples/react-native/tests/test-suite-ios-e2e.yaml

@@ -71,10 +71,6 @@ processes:
         condition: process_completed_successfully
     availability:
       restart: "no"
-    shutdown:
-      command: "metro.sh stop ios || true"
-      signal: 15
-      timeout_seconds: 5
     readiness_probe:
       exec:
         command: "metro.sh health ios ios"

examples/react-native/tests/test-suite-web-e2e.yaml

@@ -57,10 +57,6 @@ processes:
         condition: process_completed_successfully
     availability:
       restart: "no"
-    shutdown:
-      command: "metro.sh stop web || true"
-      signal: 15
-      timeout_seconds: 5
     readiness_probe:
       exec:
         command: "metro.sh health web ios"