feat(ttp): E.3.17 worker registration + scoped schemathesis suite

Wires decnet-ttp as a first-class worker:

* `decnet ttp` CLI command (master-only via MASTER_ONLY_COMMANDS)
* deploy/decnet-ttp.service.j2 systemd unit (After= identity / intel
  / reuse-correlator workers; ProtectHome=read-only since
  FilesystemRuleStore only reads ./rules/ttp/)
* deploy/decnet.target Wants= chain extended with decnet-ttp.service
* `ttp` was already in web/worker_registry.KNOWN_WORKERS

tests/api/test_schemathesis_ttp.py: TTP-routes-only schemathesis
suite, filtered via the OpenAPI tags=["TTP Tagging"] annotation
shared by the eight TTP routes. Reuses the live uvicorn subprocess
the wider test_schemathesis spawns; max_examples=400 keeps the
focused gate fast for E.3.13–E.3.16 iteration.

wiki-checkout/Service-Bus.md committed in its own repo: ttp.tagged
and ttp.rule.fired.<id> flipped from "reserved (TTP worker)" to
"decnet.ttp.worker" now that the worker publishes them.

decnet/cli/gating.py

@@ -30,6 +30,7 @@ MASTER_ONLY_COMMANDS: frozenset[str] = frozenset({
     "mutate", "listener", "profiler",
     "services", "distros", "correlate", "archetypes", "web",
     "db-reset", "init", "webhook", "clusterer", "campaign-clusterer",
+    "ttp",
 })
 MASTER_ONLY_GROUPS: frozenset[str] = frozenset(
     {"swarm", "topology", "geoip", "realism"}