Feat v0.3.5 settings audit, ICD, clone + v0.3.6 roadmap

v0.3.5 deliverables:
- Clone endpoint (POST /workflows/:id/clone) with deep stage copy
- 7 engine integration tests (28 total): lifecycle, branch routing,
  public entry, signoff gate, rejection, cancel, error cases
- Settings audit: staleness_timeout_hours + branch_rules UI in
  team-admin workflow editor
- ICD: fixed stale schemas, added ~20 new endpoint paths for
  instances, assignments, signoffs, public entry, clone, team roles

Roadmap additions (v0.3.6–v0.3.8):
- v0.3.6: 4 example workflow packages + demo surface proving
  public entry, branch rules, Starlark automation, signoff gates,
  HTTP webhooks end-to-end
- v0.3.7: package audit for non-chat packages
- v0.3.8: builder image + bundled packages for zero-config first run

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

CHANGELOG.md

@@ -2,6 +2,35 @@
 
 All notable changes to Switchboard Core are documented here.
 
+## v0.3.5 — Settings Audit + ICD + Tests + Clone
+
+### Added
+
+- **Clone endpoint**: `POST /api/v1/workflows/:id/clone` deep-copies a workflow
+  and all its stages. Creates an inactive draft with "Copy of" prefix. Handles
+  slug collisions with auto-suffix. Team-scoped mirror at
+  `/api/v1/teams/:teamId/workflows/:id/clone`.
+- **Integration tests**: 7 new engine-level tests in `workflow_engine_test.go`
+  covering full lifecycle, branch routing, public entry, signoff validation gate,
+  signoff rejection, cancel-clears-assignments, and error cases. Total: 28 tests.
+- **Staleness timeout UI**: `staleness_timeout_hours` input added to workflow
+  editor in team-admin settings (was backend-only since v0.3.3).
+- **Branch rules UI**: Collapsible JSON textarea in stage form for configuring
+  conditional routing rules (was backend-only since v0.3.2).
+
+### Changed
+
+- **ICD (OpenAPI spec)**: Fixed stale `Workflow` schema (added `description`,
+  `branding`, `is_active`, `on_complete`, `retention`, `staleness_timeout_hours`).
+  Fixed stale `Stage` schema (removed `history_mode`/`transition_rules`, updated
+  `stage_mode` enum to `[form, review, delegated, automated]`, added `audience`,
+  `stage_type`, `starlark_hook`, `branch_rules`, `stage_config`, `sla_seconds`,
+  `auto_transition`, `assignment_team_id`, `surface_pkg_id`).
+  Added `WorkflowInstance`, `WorkflowAssignment`, `WorkflowSignoff` schemas.
+  Added ~20 new endpoint paths: instances, assignments, signoffs, public entry,
+  clone, and team roles. Added tags: Workflow Instances, Workflow Assignments,
+  Workflow Signoffs, Public Workflows.
+
 ## v0.3.4 — Team Roles + Multi-party Validation
 
 ### Added