fix(analytics-platform): disable INSERT quorum in local dev so lazy precompute does not hang

[lricoy]

Problem

Local dev runs against a single-replica ClickHouse, but the lazy computation framework hardcodes insert_quorum: \"auto\" on every INSERT. On a single-node setup, ClickHouse writes immediately but still blocks on the quorum protocol — the INSERT then hits the 600s max_execution_time and dies with:

Code: 319. Unknown quorum status. The data was inserted in the local replica
  but we could not verify quorum. Reason: Timeout while waiting for quorum:
  Insertion status: Wrote 1 blocks and N rows on shard 0 replica 0

Every fresh lazy precompute request hangs for 10 minutes locally, fails, and falls through to the live path. Tests already had a special case for this (PREAGGREGATION_INSERT_QUORUM = 0 if TEST else "auto"), but DEBUG mode didn't.

Changes

Extend the existing TEST exemption to also cover DEBUG=True. Prod (DEBUG=False, TEST=False) behavior is unchanged — auto still waits for majority quorum on multi-replica clusters.

How did you test this code?

I'm an agent — no manual UI testing claimed.

• Locally: WebOverview lazy precompute request went from hanging 600s → completing in ~1.1s. INSERT succeeds with usedLazyPrecompute=True in the response. Surfaced while debugging #59075.
• hogli test products/analytics_platform/backend/lazy_computation/tests/test_lazy_computation_executor.py → 110 passed.

Publish to changelog?

no

🤖 Agent context

Agent-authored. Found by following the chain "INSERT hangs" → log says "Unknown quorum status" → single-node CH can't satisfy quorum → existing exemption already exists for TEST, just needs to also apply to DEBUG. Same shape and justification as the original TEST guard.

[greptile-apps]

_{Reviews (1): Last reviewed commit: "fix(analytics-platform): disable INSERT ..." | Re-trigger Greptile}

[deployment-status-posthog]

Deploy status

Environment	Status	Deployed At	Workflow
dev	✅ Deployed	2026-05-20 20:18 UTC	Run
prod-us	✅ Deployed	2026-05-20 20:33 UTC	Run
prod-eu	✅ Deployed	2026-05-20 20:36 UTC	Run