docs: add FleetTools — an agent-family-agnostic index of fleet capability

Every agent on nh3-dev — Claude, Codex, Grok, Aider — needs the same
answers: what runs here, how do I call it, what will bite me. Until now
that lived in ~/.claude/CLAUDE.md, which only Claude sessions load, and
it was interleaved with operator preferences that other families have
no use for.

Two-tier by design, matching the persistent-memory split: FLEETTOOLS.md
is a 135-line index an agent reads whole, and each entry links to a
detail file it opens only when it actually needs that tool. Reading the
index costs about a fifth of reading the tree.

Detail paths are absolute so they resolve from any working directory,
since a non-Claude agent will cat the path rather than follow a
markdown link. ~/FLEETTOOLS.md symlinks to the index for discovery.

Rule zero is that live inventories get queried, not transcribed:
Homepage /api/services, asset-engine /api/v1/services, LiteLLM
/v1/models, and every FastAPI seat's /openapi.json. A copied service
table would be stale within a month and this repo already has a
standing rule against second copies that drift.

Contents verified against the running fleet rather than copied from
existing docs: binaries resolved on PATH, seven endpoints probed live,
the LiteLLM roster counted at 40 models where the old note said ~30.
No credentials are included; the vault and its CLI are pointed at
instead.

docs/fleettools/henge.md

@@ -0,0 +1,23 @@
+# The Henge — durable idea parking
+
+**URL:** `http://park.phasefinal.com:8420/` (stonehenge-park, ana-docker)
+**CLI:** `park`
+
+Replaces per-repo ROADMAP parking lots for deferred ideas. Park an idea with its
+originating repo as the source; retrieve or resolve it later.
+
+```sh
+park <idea>                       # write, tagged with the originating repo
+park get     <slug>
+park promote <slug>               # it is happening
+park drop    <slug>               # it is not
+park snooze  <slug>
+park list | park search <q>       # triage; the due-queue lives in the browse UI
+```
+
+Claude Code sessions have a `/park` skill wrapping the same thing.
+
+**Why it exists:** projects sprawl at v0 when features land with no v1 target to gate
+them against — every good idea, lacking a home, silently becomes v0 scope. The gate is:
+*on the v1 path? → in; else → park it*, and **the default is park**. When both are
+defensible, park it.