The new entity-sync feature introduced A2aRequest with a `method` field
(JSON-RPC 2.0 wire format), but several test/helper files used the wrong
field name `operation` when constructing requests or logging, and checked
non-existent `.status`/`.data` attributes on A2aResponse instead of
`.result`/`.error`.
Fixes:
- asgi_app.py: log `a2a_request.method`, not `.operation` (typecheck error)
- server_lifecycle_steps.py: send `method` key in JSON-RPC payload; look
up status in `result` dict, not top-level response body
- server_lifecycle.feature: expect "healthy" (what the handler returns),
not "ok"
- entity_sync_steps.py: construct A2aRequest(method=...) not (operation=...);
assert on .result/.error instead of .status/.data
- robot/helper_entity_sync.py: same method= and result/error fixes across
sync_pull, sync_push, sync_status, sync_facade_no_service helpers
- robot/helper_server_lifecycle.py: same method= and result path fixes
ISSUES CLOSED: #1125