[iris] Introduce stores layer between transitions.py and db.py

[rjpower]

Phase 1 of the transitions -> stores -> db refactor: add ControllerStore bundling typed per-entity stores, and fold EndpointRegistry into EndpointStore. Remaining stores (Job, Task, TaskAttempt, Worker, DispatchQueue, Reservation) are skeletons to be filled in subsequent phases. ControllerTransitions now takes store= and routes endpoint ops through it; transitions.py retains a temporary self._db escape hatch for unmigrated queries.

[claude]

Claude finished @rjpower's task in 1m 15s —— View job

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Code review

Checked for bugs and CLAUDE.md / AGENTS.md compliance across all 18 modified files. Ran four parallel reviewers (2x AGENTS.md compliance, 2x bug/logic) and validated each candidate issue against the diff and repo state.

Findings (1 issue):

• 📌 transitions.py#L979-L981 — comment references plans/i-want-to-introduce-prancy-swing.md, which does not exist in the repo. Inline comment with suggested fix left on the PR.

Intentionally not flagged (false positives / deliberate design):

• self._db = store._db — PR body explicitly calls this out as a temporary escape hatch for the phased migration
• Empty skeleton JobStore/TaskStore/… classes — PR body explicitly calls these out as placeholders for subsequent phases
• Missing return-type annotations on ControllerStore.transaction() / read_snapshot() — mirrors pre-existing ControllerDB signatures; stylistic, not high-signal
• delete_task_endpoints being typed to concrete EndpointStore while peer helpers remain duck-typed — consistency nit, not a correctness issue

No bugs, no broken call sites, no misrouted store/db access. The refactor wires cleanly: every self._db.endpoints.* callsite is migrated to self._store.endpoints.*, and the register_reopen_hook mechanism correctly replaces the old ControllerDB.endpoints property.

• Review complete
  • Branch: claude/interesting-lewin-3cb93c

[claude]

The referenced plan file plans/i-want-to-introduce-prancy-swing.md does not exist in the repository (the canonical plan location is .agents/projects/, not plans/). Per AGENTS.md: "Delete stale comments immediately on discovery." Either add the plan doc or drop the reference.

Suggested change

	# Escape hatch kept only while the phased migration moves SQL out of
	# this file. Direct ``self._db`` SQL calls should decrease every phase
	# and hit zero at the end (see plans/i-want-to-introduce-prancy-swing.md).
	# Escape hatch kept only while the phased migration moves SQL out of
	# this file. Direct ``self._db`` SQL calls should decrease every phase
	# and hit zero at the end.

[yonromai]

🤖 Code review

Approved. No issues found in the current head. Checked for bugs and AGENTS.md compliance.

Validation:

• cd lib/iris && uv run --group dev python -m pytest -n1 --tb=short -m 'not slow and not docker and not e2e' tests/cluster/controller/test_endpoint_store.py tests/cluster/controller/test_transitions.py tests/cluster/controller/test_service.py tests/cluster/controller/test_dashboard.py tests/cluster/controller/test_api_keys.py tests/cluster/controller/test_auth.py tests/cluster/controller/test_task_resource_history.py tests/test_budget.py
• Result: 347 passed, 6 warnings in 63.32s
• uv run --package marin --group test python -m pytest -q tests/integration/iris/test_iris_kind.py::test_gpu_pod_attributes_with_in_memory_k8s
• Result: 1 passed, 1 warning in 0.69s

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