✨ feat(repository,cli): add namespace registry with DynamoDB records and CLI commands

[sodre]

Summary

• Add seven namespace lifecycle methods to Repository: register_namespace, register_namespaces, list_namespaces, delete_namespace, recover_namespace, list_orphan_namespaces, and purge_namespace
• Add full namespace CLI subcommand group with register, list, show, delete, recover, orphans, and purge commands
• Implement bidirectional name-to-ID registry using forward (#NAMESPACE#) and reverse (#NSID#) DynamoDB records under the reserved _/SYSTEM# partition
• Support soft-delete with optional purge: deletion is O(1) (removes forward record, marks reverse as deleted), purge queries GSI4 and batch-deletes orphaned data
• Support concurrent bulk registration via register_namespaces() using asyncio.gather / _run_in_executor
• Reserved namespace _ is rejected with ValueError across all operations
• Comprehensive unit and integration test coverage for all repository methods and CLI commands

Test plan

• Unit tests for all seven repository methods (tests/unit/test_namespace_registry.py)
• Unit tests for all CLI namespace commands (tests/unit/test_cli.py)
• Integration tests for namespace lifecycle (tests/integration/test_namespace_registry.py)
• uv run pytest tests/unit/ passes
• uv run mypy src/zae_limiter/ passes
• Sync code generation is up-to-date (hatch run generate-sync)

Closes #369

🤖 Generated with Claude Code

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.82%. Comparing base (bbc8120) to head (d50be2b).
⚠️ Report is 11 commits behind head on main.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #382      +/-   ##
==========================================
+ Coverage   91.48%   91.82%   +0.33%     
==========================================
  Files          33       33              
  Lines        7118     7385     +267     
==========================================
+ Hits         6512     6781     +269     
+ Misses        606      604       -2     

Flag	Coverage Δ
doctest	27.13% <4.46%> (-1.32%)	⬇️
e2e	40.46% <17.55%> (-1.62%)	⬇️
integration	48.53% <45.53%> (-0.69%)	⬇️
unit	91.56% <100.00%> (+0.31%)	⬆️

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[sodre]

Review: PR #382 — Namespace Registry + CLI (#369)

All 47 acceptance criteria verified against issue #369. CI green across all checks.

Acceptance Criteria Summary

Section	Criteria	Status
register_namespace	7 criteria	All pass
register_namespaces	5 criteria	All pass
list_namespaces	3 criteria	All pass
delete_namespace	5 criteria	All pass
recover_namespace	6 criteria	All pass
list_orphan_namespaces	2 criteria	All pass
purge_namespace	6 criteria	All pass
Sync + CLI	13 criteria	All pass

Code Quality Notes

• Forward + reverse records now include GSI4PK, GSI4SK, and created_at on both records — fixes the missing attributes from _register_namespace()
• generate_sync.py: Correctly handles starred args (asyncio.gather(*[expr for x in iter]) → self._run_in_executor(*[lambda x=x: expr for x in iter])) with default-arg capture to avoid late-binding closure bug
• purge_namespace: GSI4 KEYS_ONLY projection is correct — only PK/SK needed for BatchWriteItem DeleteRequests
• recover_namespace: Defensive ConditionExpression: attribute_not_exists(PK) on forward record re-creation handles name collision race

Test Coverage

• Unit: 613 lines — all methods + pagination + edge cases
• CLI: 686 lines — all 7 commands + help + error paths
• Integration: 309 lines — full lifecycle with LocalStack
• Pagination covered for all three paginated operations

One Observation (Non-Blocking)

namespace show CLI uses repo._get_client() directly instead of a public Repository method. Works correctly and tests cover it — a get_namespace() method could be added later if needed.

Closes #369. Ready to merge.

🤖 Generated with Claude Code