Complete GA4 report pagination

[indiviedualis-ui]

Why

The GA4 pagination sample only demonstrated two fixed requests and did not explain when to advance the offset. This could lead to unnecessary requests or incomplete handling of reports larger than one page.

What changed

• Iterate through report pages in 100,000-row increments.
• Use response.row_count to stop once all matching rows have been covered.
• Add a unit test verifying the expected offsets for a multi-page response.

Validation

git diff --check passes. The focused pytest could not run because Python/Pytest is unavailable in the environment.

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[indiviedualis-ui]