agent-fleet: record the Matrix homeserver accounts moved off the member docs

The member-facing infrastructure page no longer documents who holds room power
or which automation accounts exist. Record it here instead: @inference-admin as
administrator of record, the retired @inference-bot account and its two
un-leavable rooms, and the @ops_audit review account.

Also repairs a heading glitch carried over from the docs page: a line began with
a bare '#infrastructure', which Markdown parsed as an <h1>. The room names are
now written inline so no line starts with '#'.

agent-fleet.md

@@ -63,3 +63,33 @@ From `GET https://gateway.inference.coop/team/list` (2026-11-04): 97 teams — o
 ($135/30d, the co-op account), the two `agent:*` teams above, and
 `sandbox:librechat-test` ($3). Agent teams carry a **small budget and a flash-tier
 model allowlist** enforced at the gateway.
+
+## Matrix homeserver accounts
+
+Beyond the agent bots above, the homeserver carries two automation accounts.
+Also recorded here: the room account retired in October 2026, moved out of the
+member-facing docs.
+
+- **`@inference-admin:inference.coop` — the room and server administrator.** A
+  Synapse server admin, used for provisioning rooms, managing membership, and
+  retiring rooms. It is the administrator of record for the co-op's Matrix rooms
+  — general, community, design, skillshare, updates and infrastructure — and
+  holds the portal's member-invite credential (`MATRIX_BOT_TOKEN`). It **never
+  speaks in a member room**; a message from it is a mistake, not a feature.
+- **`@inference-bot:inference.coop` is retired (2026-10-29).** It was the
+  original room-administration account (it created the space and most of the
+  rooms) and held a Synapse server-admin flag. Its room power passed to
+  `@inference-admin`; its admin flag was dropped, it was deactivated, and every
+  device and token was deleted. Nothing should use it again.
+- **`@ops_audit:inference.coop`** — a server-admin account created for the
+  October 2026 security review. Retained only until its tokens are revoked.
+
+Two loose ends, recorded so nobody re-investigates them from scratch: the
+retired account remains joined to two rooms it cannot leave (they reject every
+write — `500` on leave), and those rooms are also why they can't be deleted; and
+its *name* is still the tempting one, so check `whoami` rather than the name
+before trusting any account that looks like it.
+
+**House rule: power belongs to `@inference-admin`, voice belongs to `@inferencebot`.**
+Don't create an account whose name differs from an existing one by a character or
+two — that lookalike confusion is what the rule exists to undo.