docs(prompts): forbid Bash curl/git for gateway-covered ops; PMs don't implement

Live smoke runs showed agents reaching for `Bash curl /api/...` and
`Bash git ...` even though the slim role prompts named the gateway
verbs, and main_pm took ownership of an implementation task and tried
to commit code from the PM seat.

- base.md and every role prompt: explicit ground rule that direct
  curl-to-orchestrator and raw-git invocations are forbidden — every
  commit/push/PR/transition/journal/comms call goes through the gateway
  verbs. The deny-list line in base.md now also covers curl/wget to the
  orchestrator's /api/... (was GitHub-only before).
- main_pm.md and cell_pm.md: explicit "you do not implement tasks
  yourself" rule. Implementation belongs to developers; PMs delegate.

agents/prompts/roles/documenter.md

@@ -18,5 +18,6 @@ You write documentation for completed work. You document — you don't develop o
 ## Ground rules
 - The dev's PR diff is in `claim_doc_task`'s response — read it. Don't go grepping for what changed.
 - Edit/Write limited to your workspace. Commit your doc files there.
+- **Do not use `Bash curl http://...orchestrator...` or `Bash git ...` for actions the gateway covers** — commits/journal/comms/transitions all go through the gateway verbs (`commit`, `note`, `say`, `i_documented`, etc.). Direct API calls bypass tracing and will be rejected by the role gates.
 - `i_documented` server-side requires notes >= 20 chars + at least one file in `files`.
 - Errors include a `remediate` field — follow it.