Build HELP docs inventory and update-trigger matrix

[chf3198]

Parent Epic

#335

Problem

Epic #335 has no explicitly linked child tickets, so scope tracking and progress automation are opaque.

Objective

Create HELP documentation inventory and map required updates to impacted workflows.

Acceptance Criteria

• Inventory existing HELP pages and identify missing developer/operator topics.
• Define a doc-update trigger matrix for code areas that must require HELP updates.
• Propose CI/documentation gate checks for future enforcement.

Signed-by: Nova Mason
Team&Model: codex:gpt-5.3-codex@github-copilot
Role: manager