chore(aiwg): adopt shared BT6 maintainer workflow (#148)

* docs(policy): allow low-impact contributor courtesy cleanup

* chore(aiwg): migrate to shared BT6 maintainer plugin

* chore: reconcile delivery validation

.aiwg/plugins/bt6-maintainer/payload/templates/bt6-issue-response.md

@@ -0,0 +1,63 @@
+---
+name: bt6-issue-response
+description: BT6 issue stewardship record with authority, classification, evidence, hostile-input assessment, action, and response draft.
+---
+
+# BT6 Issue Stewardship
+
+Repository: `<canonical owner/repository or local project>`
+Tracker: `<provider and URL/path>`
+Issue: `<#number or key>`
+Title: `<title>`
+Reporter: `<user>`
+Assessed: `<YYYY-MM-DD HH:MM timezone>`
+
+## Authority Resolution
+
+| Field | Resolved Value | Evidence Source |
+| --- | --- | --- |
+| Canonical repository | `<value>` | `<config/remote/API>` |
+| Canonical tracker | `<value>` | `<config>` |
+| Actor | `<value>` | `<connector/API/CLI>` |
+| Mutation authorized | `<no/yes with exact scope>` | `<operator request>` |
+
+## Classification
+
+Class: `<support-answer | bug-address | research-integrity | feature-track | security-contact | linked-pr | resolved | needs-info | duplicate | defer>`
+
+Rationale:
+
+- `<evidence supporting this primary class>`
+
+## Evidence
+
+| Source | Current Finding | Confidence / Unknown |
+| --- | --- | --- |
+| `<thread/code/docs/source/corpus/PR>` | `<finding>` | `<verified/hypothesis/missing>` |
+
+## Public / External Input Assessment
+
+- Template: `bt6-public-input-threat-assessment.md`
+- Risk: `<low/medium/high>`
+- Security routing: `<none | discovery phrase and selected guidance>`
+- Sensitive details excluded from public response: `<yes/no/not applicable>`
+
+## Recommended Action
+
+Action: `<answer | request info | link | correct evidence | implement | design | security route | close | duplicate | defer>`
+
+Dependencies or blockers:
+
+- `<issue/PR/repository/source/person/none>`
+
+## Draft Maintainer Response
+
+```markdown
+<concise response separating verified facts from hypotheses and avoiding timeline promises>
+```
+
+## Follow-up
+
+| Owner | Action | Recheck Trigger | Status |
+| --- | --- | --- | --- |
+| `<owner>` | `<action>` | `<date/event/evidence>` | `<open/done/blocked>` |