Create library upgrade to smoke test mapping document

[sharon-fdm]

Goal

User story
As a Fleet engineer,
I want a document that maps each third-party library to a set of smoke tests,
so that when we upgrade a library, we know exactly which smoke tests to run to validate the upgrade.

Context

When we upgrade a dependency, there is no systematic way to know what functionality is at risk or what to test. Engineers rely on tribal knowledge or run the full test suite and hope for the best. A mapping document closes this gap by making the relationship between libraries and testable surface areas explicit.

Deliverable

The complete library-to-smoke-test mapping document lives in the handbook:

handbook/engineering/library-upgrade-smoke-tests.md (PR: #48949)

Covers all ~353 direct dependencies across every module, organized by functional area, with concrete smoke tests and risk levels for each.

Changes

Engineering

• Audit go.mod, tools/*/go.mod, and package.json for all direct dependencies
• For each dependency, identify which Fleet subsystems use it (search for imports)
• Define smoke tests for each dependency or dependency group
• Assign risk levels
• Write the mapping document and check it into handbook/engineering/
• Review with engineering leads for completeness

Product

• No UI, CLI, API, YAML, agent, or configuration changes

Risk assessment

• Risk level: Low
• Internal documentation change only, no code changes