fix: follow helper input access in config sync

[TheRealAgentK]

Summary

Fixes a false positive in check_config_sync.py where schema parameters accessed through simple module-local helpers were reported as unused.

The checker now preserves direct execute() scanning and additionally follows statically named module-local helper calls when an action passes its inputs object, for patterns like _pagination_params(inputs).

Scope

• Supports helper parameter aliases such as action_inputs.
• Preserves direct vs .get() classification for required/optional consistency checks.
• Keeps analysis intentionally limited to module-local functions with static names.
• Does not analyze imported functions, method calls, dynamic calls, nested closures, or complex control flow.

Tests

• Added focused pytest regressions for direct access, helper-only access, helper required/optional classification, non-calling action isolation, and new-integration fatal drift behavior.
• Wired the focused pytest regressions into the self-test workflow.
• Updated the config-sync docs to describe the limited helper-call support.

Validation

• .venv/bin/pytest tests/test_check_config_sync.py
• .venv/bin/ruff check scripts/check_config_sync.py tests/test_check_config_sync.py
• .venv/bin/ruff format --check scripts/check_config_sync.py tests/test_check_config_sync.py
• From autohive-integrations: .venv/bin/python ../autohive-integrations-tooling/scripts/check_code.py --base-ref origin/master missive

[Olwiba]

This looks like a nice set of changes :)