[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.