[jallegri]

Summary

• Distinguish unreleased SDK 0.2.0 from the published 0.1.2 package and provide a reproducible installation.
• Correct query database names and CQ time placeholders; explain complete replacements, partial updates, and uncertain retention outcomes after timeouts.
• Keep compatibility with other Arc releases explicitly unverified. Documentation only.

Test plan

• All 24 Python blocks parse.
• README CQ creation and actual aggregation passed with sync/async clients against Arc v26.09.3 and SDK 539505c.
• Corrected public documentation and pinned revision links return HTTP 200.
• Independent documentation review completed; the CQ source-qualification finding was fixed and verified with real execution.
• Review with xe-nvdk before merge.

SDK 0.1.2 regression compatibility and the remaining Arc v26.x release matrix are separate pending validation; this PR does not claim those checks passed.

[xe-nvdk]

The measurement-name and link fixes, the scheduler-licensing wording and the CQ {start_time}/{end_time} example are good.

One blocker: the new header pins the README to commit 539505c, which goes stale on the next merge to main. We've decided 0.2.0 ships alongside Arc 2027.01.1, so I'd drop that block, or replace it with a single line: "main tracks the unreleased 0.2.0; the latest PyPI release is 0.1.2", with no install-from-commit instructions.

[xe-nvdk]

Thanks @jallegri. We took this over to finish it: merged main in and pushed da483cc. Your fixes are all kept, and I checked them against a live Arc:

• CQ example: the one on main really fails, with 400: query must contain {start_time} and {end_time} placeholders. Yours creates the CQ.
• Query table names: the unqualified FROM cpu query returns the written row.
• Licensing note: the CQ and retention schedulers are Enterprise-licensed in Arc.
• Code blocks: all 31 Python blocks parse.

Three changes on top:

1. Removed the banner pinning 539505c with a git install. main is 44 commits past it, and this README becomes the PyPI page when 0.2.0 ships, so it would send users to an old commit. A one-line note after the install commands says the README documents 0.2.0.
2. "On affected server versions" now names them: Arc 26.09.3 and earlier. Their history endpoint skips running retention executions because the NULL duration fails the row scan (Arc#1415). Fixed in 27.01.1.
3. Dropped "other Arc releases are still being validated": that's QA status rather than reader guidance.

Marking ready for review.