fix(bmm-skills): address remaining PR review nits

- headless-schemas.md: Update schema gains `external_handoffs` to match
  SKILL.md which routes Update through Finalize (handoffs execute there).
- bmad-product-brief/SKILL.md: "Use the bmad-help skill" → "Invoke
  bmad-help" to align with REF-03 and the bmad-prd phrasing.
- bmad-product-brief/SKILL.md: hyphenate "high-quality draft".

src/bmm-skills/1-analysis/bmad-product-brief/SKILL.md

@@ -75,7 +75,7 @@ Conversationally surface what the user brings, why this brief exists, and the do
 ## Finalize
 
 1. Decision log audit + addendum review: the user ends this step with an explicit, shared accounting of how the meaningful contents of `decision-log.md` were handled — captured in the brief, captured in `addendum.md` (which may already hold detail captured during the conversation — see `## Constraints` for what belongs there), or set aside as process noise.
-2. Polish: apply each entry in `{workflow.doc_standards}` (a `skill:`, `file:`, or plain-text directive) to `brief.md` (and `addendum.md` if it exists). Run passes as parallel subagents - apply all doc standards to `brief.md` first, then `addendum.md` so we present a high quality draft for the user to review and finalize.
+2. Polish: apply each entry in `{workflow.doc_standards}` (a `skill:`, `file:`, or plain-text directive) to `brief.md` (and `addendum.md` if it exists). Run passes as parallel subagents - apply all doc standards to `brief.md` first, then `addendum.md` so we present a high-quality draft for the user to review and finalize.
 3. External handoffs: execute each entry in `{workflow.external_handoffs}` to route artifacts beyond local files (Confluence, Notion, ticket systems, etc.) — each directive names the MCP tool and the fields it needs. Invoke the tool, capture any URLs or IDs returned, and surface them in the user message. If a named tool is unavailable, skip that handoff and flag it; local files always exist regardless.
-4. Tell the user it is ready: local paths and external destinations (URLs returned from handoffs). Use the `bmad-help` skill to suggest what next steps make sense in the bmad method ecosystem.
+4. Tell the user it is ready: local paths and external destinations (URLs returned from handoffs). Invoke `bmad-help` to suggest what next steps make sense in the bmad method ecosystem.
 5. Run `{workflow.on_complete}` if non-empty. Treat a string scalar as a single instruction and an array as a sequence of instructions executed in order.

src/bmm-skills/2-plan-workflows/bmad-prd/assets/headless-schemas.md

@@ -37,7 +37,10 @@ Every headless run ends with one of these payloads. Omit keys for artifacts not
   "decision_log": "{doc_workspace}/decision-log.md",
   "changes_summary": "1-3 sentences describing what changed and why",
   "conflicts_with_prior_decisions": [],
-  "open_questions": []
+  "open_questions": [],
+  "external_handoffs": [
+    {"directive": "Confluence upload", "tool": "corp:confluence_upload", "url": "https://confluence.corp/PROD/123", "status": "ok"}
+  ]
 }
 ```