docs: accept SEP 47, backend-owned execution sessions

docs/dev/roadmap.md

@@ -35,6 +35,20 @@ being implemented.
   routes, bound response and other geometries remain follow-up work; the first route is
   a single-mode capillary with node quadrature.
 
+- [SEP 47 — Backend-owned execution sessions](seps/sep-0047-run-ownership.md):
+  make each backend own its numerical run, including stepping, observations, boundaries,
+  statistics, accounting and export preparation, while Python owns the scientific
+  description and external services. Replace native driver inheritance and mirrored
+  state with typed descriptors and a session protocol; native exposes its complete
+  session, while the independent NumPy oracle uses a host session in both retained
+  precisions. Retire MLX early, without porting it. Backend lowering owns packing, chunks
+  and workspace lifetimes; include #346 saved-plane copies and #361 device chunks, and
+  move PR #598's CPU transform policy (#584) into lowering. Include independent snapshot
+  requests, cooperative stopping and explicit restart reporting. Device capabilities keep
+  their per-vendor status. Delivered through a few phase PRs under a recorded SEP 0
+  exception; APIs may be freely broken for a cleaner design, with callers, tests and
+  documentation updated together and a changelog listing.
+
 ## Draft enhancement proposals
 
 SEPs under discussion; their scope may change and implementation has not been accepted.

docs/dev/seps/index.md

@@ -33,6 +33,7 @@ Proposals that are active, in draft, accepted, in progress or deferred.
 | [11](sep-0011-finite-density-gas-index.md) | Finite-density gas index and mixture optics | Draft | Change |
 | [17](sep-0017-gas-two-photon-ionisation.md) | Broadband two-photon continuum response beside strong-field ionisation | Accepted | Feature |
 | [32](sep-0032-raman-maxwell-bloch.md) | Raman Maxwell–Bloch dynamics | Draft | Feature |
+| [47](sep-0047-run-ownership.md) | Backend-owned execution sessions | Accepted | Change |
 
 SEP 13, the standalone numerical prerequisite for SEP 12, SEP 14, which carried it to
 the compiled backends, and SEP 16, which unified the multistep family and made it the
@@ -98,6 +99,7 @@ sep-0010-low-rank-raman
 sep-0011-finite-density-gas-index
 sep-0017-gas-two-photon-ionisation
 sep-0032-raman-maxwell-bloch
+sep-0047-run-ownership
 template
 archive/index
 ```

docs/dev/seps/sep-0000-process.md

@@ -380,3 +380,9 @@ that edits this document and adds a line to its history.
 - 2026-11-04: A SEP's branch stacks only on another agent's open pull request, and one agent's
   work isn't divided across a stack, since every pull request and push runs CI's whole
   matrix (maintainer's decision).
+- 2026-11-09: John Travers approved a narrow exception for
+  [SEP 47](sep-0047-run-ownership.md#11-phases): its implementation may merge through
+  a small number of coherent phase PRs, each leaving main usable with green required
+  CI. Temporary internal adapters are removed by Final, and its Implementation field
+  retains the successive milestone branches and PRs. The general one-branch/one-PR
+  rule is unchanged; this records the delivery exception, not acceptance of SEP 47.