chore: update CP APIs to support namespace re-design

[nborges-aws]

Summary:

Migrates the memory control-plane to the new namespaceTemplates field, deprecating the legacy namespaces field while maintaining full backward compatibility.

Description of changes:

• MemoryClient (memory/client.py) — 13 methods updated with parallel namespace_templates kwargs
• MemoryControlPlaneClient (memory/controlplane.py) — parallel namepsace_templates kwargs
• Episodic methods gained reflection_namespace_templates, deprecating reflection_namespaces

Behavior changes for users

• No breaking changes. All existing code using namespaces= / reflection_namespaces= continues to work, with a DeprecationWarning surfaced to encourage migration.
• Calling a method with both namespaces= and namespace_templates= raises ValueError with a message pointing users to the new name.

Testing

• New TestResolveNamespaceTemplates unit tests cover the happy paths, mutual exclusivity, and deprecation warning emission
• Existing method tests updated to assert on the new namespaceTemplates key rather than namespaces. Existing legacy-kwarg callers in tests are preserved as DeprecationWarning-triggering coverage for the backward-compatible path.
• Full suite passing : 1706 passed, 0 failures. 16 DeprecationWarnings are expected — messaging for legacy namespace field

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[github-actions]

✅ No Breaking Changes Detected

No public API breaking changes found in this PR.