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.

deploy/decnet.target

@@ -18,6 +18,7 @@ Wants=decnet-bus.service \
       decnet-enrich.service \
       decnet-clusterer.service \
       decnet-campaign-clusterer.service \
+      decnet-ttp.service \
       decnet-webhook.service \
       decnet-canary.service \
       decnet-orchestrator.service