Follow-up for salvaged PR #65453: extend the regression test to dispatch a
real memory_tool add through the store the tool executor wires in, assert the
write persists to memories/MEMORY.md, and assert the external memory provider
(MemoryManager) is still skipped under skip_memory=True. Also map the
contributor email for attribution CI.
Fixes#65429.
Behavioral test constructing a real AIAgent with skip_memory=True and
enabled_toolsets=["memory"] asserts the built-in MemoryStore is created
(store is not None). Also covers the negative case (no memory toolset -> None)
and the normal case (skip_memory=False -> store created).