refactor: split deployment seeding and dashboard responsibilities

[josedab]

Summary

• Restores complete Helm/Compose/shell validation and separates seeder runtime, fixtures, and Grafana dashboard resources.
• Preserves repository public contracts while restoring or strengthening the verification baseline.
• Includes an AUDIT.md where the repository reached the audit/refactor phase.

Commits

• c30f060 fix(deploy): restore complete validation baseline
• 6453de4 docs(deploy): record clean-code audit
• 282295a test(deploy): characterize SRP seams
• 870cff2 refactor(deploy): move seeding responsibilities (DEP-SRP-1)
• 5fa8dc9 refactor(deploy): clarify seeding workflow (DEP-SRP-1)
• 8601ee0 refactor(deploy): split Grafana dashboards (DEP-SRP-2)
• a4dfe88 refactor(deploy): centralize Grafana metadata (DEP-SRP-2)
• 8a365b9 fix(deploy): package seeder libraries
• 9913bf2 fix(ci): allow Helm plugin installation

Validation

Helm lint/render, 35 unit tests, Compose validation, seeder characterization, Docker packaging, and ShellCheck pass.

Known blockers / deferred work

• None beyond required PR checks and documented AUDIT.md deferrals.

Merge readiness

Ready for review. Merge only after all required GitHub checks and reviewer approvals pass.