docs: fix vale errors on main

Fix the 4 pre-existing vale error-level hits on main (docs/README.md:83,
docs/getting-started/setup.md:11,127, docs/swarm/bao.md:4) that fail CI's
prose-lint-errors job for every docs PR regardless of its own diff.

docs/README.md

@@ -80,7 +80,7 @@ declarations.
   where's that shape headed?** → [`swarm/credentials.md`](swarm/credentials.md)
   (current state, target state, and the progressive-enhancement rule);
   [`swarm/secrets.md`](swarm/secrets.md) for where each file lives today.
-- **How does the secret store come up, who writes its grants, how is it
+- **How does the secret store come up, who writes its grants, how's it
   sealed?** → [`swarm/bao.md`](swarm/bao.md).
 
 ## Scheduler, CI, observability

docs/getting-started/setup.md

@@ -8,7 +8,7 @@ each one assumes the ones before it.
 Every command runs as **root on the host**.
 
 > **Not all-local?** Each step says which host it runs on. A split swarm
-> also has credentials that can't be generated where they're read — each
+> also has credentials you can't generate where they're read — each
 > host's mTLS identity at the secret store, and each hive's telemetry
 > ingest secret. Read [`swarm/secrets.md`](../swarm/secrets.md) first; it
 > says which files you place, and where.
@@ -124,7 +124,7 @@ swarmctl agent create iris --hive pr1ma
 
 The controller provisions iris's identity, forge user and config repo
 (`agent-configs/iris`, from the default template), then has the hive build
-and start the container. It returns once the job is queued — watch the
+and start the container. It returns once the scheduler queues the job — watch the
 swarm UI's job view for progress.
 
 Later config changes are PRs on `agent-configs/iris`, approved by you. →

docs/swarm/bao.md

@@ -1,7 +1,7 @@
 # The swarm secret store (OpenBao)
 
 The swarm runs one OpenBao store, `swarm-bao`. Every swarm-level
-credential an agent or service needs is fetched from it under that
+credential an agent or service needs comes from it under that
 principal's own certificate identity. What lives in it and who reads what:
 [`secrets.md`](secrets.md). This page covers the store itself — how it
 comes up, who may write its grants, and how it's sealed and reached.