docs: migrate legacy specs and add product context (#2964)

docs/plans/github-executor-clone-transport/plan.md

@@ -1,5 +1,5 @@
 ---
-spec: docs/specs/integrations/github-authentication.md
+spec: docs/specs/integrations/requirements/github-authentication.md
 created: 2026-07-28
 status: complete
 ---

docs/plans/github-executor-clone-transport/task-00-reconcile-managed-checkout-origin.md

@@ -5,7 +5,7 @@ status: done
 wave: 1
 depends_on: []
 plan: "plan.md"
-spec: "../../specs/integrations/github-authentication.md"
+spec: "../../specs/integrations/requirements/github-authentication.md"
 ---
 
 # Task 00: Reconcile Managed Checkout Origin
@@ -48,7 +48,7 @@ node scripts/validate-public-docs.mjs
 - `apps/backend/internal/orchestrator/executor/executor_resume_clone_transport_test.go`
 - `apps/backend/internal/orchestrator/executor/executor_resume_clone_default_branch_test.go`
 - `docs/public/integrations.md`
-- `docs/specs/integrations/github-authentication.md`
+- `docs/specs/integrations/requirements/github-authentication.md`
 - this task file and `plan.md`
 
 ## Dependencies