[codex] Document SDK feed parameter units

[tamlut-modnys]

Summary

• Clarify SDK README guidance for raw v2 feed parameters, SDK helper maxVariance, quorum fields, and value scaling.
• Update JS/TS JSDoc and Rustdoc comments so helper-level maxVariance and raw scaled fields are not confused.
• Add comments to Aptos example scripts and Surge metadata code where maxVariance / max_job_range_pct values appear.

Why

The same concept is exposed through multiple surfaces with different units. SDK helpers may accept human percentages and scale internally, while raw gateway and v2 feed fields expect 1e9-scaled integers.

Validation

• Ran the user-docs boundary scanner on touched README files.
• Ran a search audit for maxJobRangePct|max_job_range_pct|maxVariance|max_variance|max_range_percent|minJobResponses|minOracleSamples|RangeExceeded.
• Ran git diff --check.
• TypeScript checks were not run because codex-in-container could not start Colima: ha.sock ... connection refused before entering the container.

[tamlut-modnys]

Closing this direct SDK PR because SDK changes should be authored in sbv3 and synced into switchboard-sdk by Copybara. Replacement PR: https://github.com/switchboard-xyz/sbv3/pull/1029