docs: residual handoff in hub docs, AGENTS, and templates

Align agent close/workplan finish with fleet residual convention
(live work records, origin residual + origin_ref). Reference pages for
work-records and intakes; session and workplan templates updated.

docs/workplan-convention.md

@@ -44,3 +44,16 @@ Use `proposed` for a new plan that still needs review, `ready` after it has
 been checked against the current repo state, and `finished` when implementation
 is complete. `stalled` and `needs_review` are derived health labels, not stored
 frontmatter statuses.
+
+### Residuals when finishing
+
+If work remains after a plan is complete, **do not** leave it only as prose or
+in `SCOPE.md`. Before `status: finished`, hand off each actionable residual as
+a live work record:
+
+- parkable Green/Blue → **intake** with `origin: residual`, `origin_ref: <WP-id>`
+- multi-step → **new workplan** (optional promote from residual intake)
+- founder gate/time → **decision** / **engagement**
+
+Canon: `the-custodian/canon/standards/work-record-types_v0.1.md` § Residuals.
+Hub index/list: State Hub (not domain-local residual files).