docs: capture a rule the plans deletion would erase

openspec/changes/specify-documentation-homes/design.md

@@ -161,3 +161,29 @@ drops the others.
 *Alternative considered:* convert `CLAUDE.md` to a pointer first and sort the
 content afterwards. The conversion is what forces the decision about each block,
 so deferring it means writing a `CONTRIBUTING.md` that has to be rewritten.
+
+## One rule was about to be deleted with its only record
+
+Reviewing the 76 planning documents before removal, as section 4 requires, found
+seventy that were implementation choreography for shipped work and six that
+carried decision rationale. Five of the six describe architecture that the
+repository still documents. One does not.
+
+The unified-domain-endpoint plan decided to remove `POST /job` and route all job
+creation through domain endpoints. The rule still binds — the only `post:`
+remaining on the job API is `/api/job/{id}/retry`, an action on an existing job
+rather than a way to create one — but no current document states it. Not
+`api-guidelines.md`, not `architecture.md`, not `CLAUDE.md`.
+
+That makes it invisible in a specific way: the rule is expressed as an endpoint
+that is *absent*, so nothing a reader opens will mention it, and a contributor
+adding a domain has no way to discover the constraint before violating it.
+
+Relocating what the architecture documents say would not have produced this
+requirement, because those documents do not say it. It needed its own task, or
+deleting the planning directory would have removed the last written record of a
+rule still in force.
+
+*Alternative considered:* keep the plan that records it. Rejected — a planning
+document is not where a binding rule belongs, and keeping one file to preserve
+one sentence reintroduces the directory this change removes.

openspec/changes/specify-documentation-homes/tasks.md

@@ -35,6 +35,11 @@
   messages, linting, and test conventions across `CLAUDE.md`, `development.md`,
   and `testing.md` before the root `CONTRIBUTING.md` is written, so the
   conversion has one source to draw from
+- [ ] 3.9 `osapi` — capture "job creation goes through domain endpoints" as a
+  requirement. Removing `docs/plans/` deletes its only written record: the rule
+  still binds (the sole `post:` on the job API is `/api/job/{id}/retry`, an
+  action on an existing job) but is stated in no current document, so relocating
+  what `api-guidelines.md` and `job-architecture.md` say will not produce it
 - [ ] 3.7 Leave each source document in place as a pointer to the capability
 - [ ] 3.8 `osapi` — leave `architecture.md`, `system-architecture.md`, `ui.md`,
   and the eight-step "Adding a New API Domain" walkthrough in the repository;