docs(fleettools): autoload for Codex and Grok, and a vaulted gateway key

Codex reads a global AGENTS.md from CODEX_HOME; Grok always scans
~/.grok/rules/ and loads every *.md in it regardless of name. Both were
empty, so AGENT-BOOTSTRAP.md is symlinked into each rather than copied
— one file, three agent families, no drift surface.

The bootstrap is a pointer, not a second index: it names
~/FLEETTOOLS.md, gives the three live-inventory endpoints, and inlines
only the rules that must hold even if the agent never opens anything
else — attribution to Vuong Hoang, no committed secrets, the operator
owns architectural calls, n=1 is not a measurement, and absence of a
signal is not a safe reading of it.

The shared all-agents LiteLLM key was single-copy in ~/.claude/CLAUDE.md
and is now also in the vault at litellm/all-agents-shared-key, per the
standing directive that durable credentials never live in one place.
It stays inline in CLAUDE.md too, since every session needs it and a
vault round-trip measured over two minutes. Namespace is service-scoped
rather than host-prefixed because the key is fleet-wide, matching the
existing att/fortigate/headscale/unifi/worldtree entries.

docs/fleettools/litellm.md

@@ -19,7 +19,7 @@ The gateway **401s without a virtual API key**. Three tiers:
 
 | key | where | reach |
 |---|---|---|
-| shared all-agents (`all-agents-local`) | `~/.claude/CLAUDE.md` § Global tools | **every** model, paid passthroughs included |
+| shared all-agents (`all-agents-local`) | `secret get litellm/all-agents-shared-key`, also inline in `~/.claude/CLAUDE.md` § Global tools | **every** model, paid passthroughs included |
 | infra-ops admin | `~/.config/litellm/infra-ops-key` (0600) | admin operations |
 | project-scoped | request from infra-ops via althing | isolated, auditable spend |