[DOC-12247] Explain ordering within array aggregates

[sfc-gh-qding]

Summary

DOC-12247: Explain ordering within array aggregates.

Docstring-only clarification of existing API behavior. No executable implementation, signatures, shared state, AST encoding, credentials, dependencies, logging, or telemetry changes.

Validation

Read-only Snowhouse query on VALUES verified ordered DISTINCT array [1,2] and ordered duplicate-preserving array [1,2,2]. Query ID 01c76927-091a-ca41-0001-dd97437250f3. Existing is_distinct example differs in the local emulator; server semantics checked rather than claiming local parity.

• Python AST comparison with docstrings removed confirms runtime code unchanged.
• Sphinx/Napoleon and docutils parsing: no new warnings. Repository-pinned Black 22.3.0 and git diff checks passed.
• Overlapping session.py, dataframe.py, and array_agg documentation edits merge cleanly pairwise.
• Full SDK integration and full Sphinx builds deferred to CI. Local tests used isolated Python 3.11 and Snowpark 1.55.0 with localtest; mocks are not live integration validation.

Required acknowledgments

• I acknowledge that I have ensured my changes to be thread-safe.
• If adding any arguments to public Snowpark APIs or creating new public Snowpark APIs, I acknowledge that I have ensured my changes include AST support.

NO-CHANGELOG-UPDATES: documentation-only, no runtime behavior change.

Generated with Snowflake CoCo

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 95.43%. Comparing base (5ab7287) to head (4a54353).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4403      +/-   ##
==========================================
- Coverage   95.44%   95.43%   -0.01%     
==========================================
  Files         176      176              
  Lines       45271    45271              
  Branches     7759     7759              
==========================================
- Hits        43209    43206       -3     
- Misses       1282     1283       +1     
- Partials      780      782       +2     

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[sfc-gh-qding]

Superseded by consolidated PR #4407: #4407 . This change is preserved in the combined branch and was revalidated with the other nine documentation fixes. Closing only this PR; the associated Jira remains open until #4407 merges.