Say when the mesh is wrong: conditions, watchdogs, the bus's advisories, doctor (hq to-be 45 Phase 1)

Every one of the 48 core failures of research 031 was found by a person
looking; the mesh's answers carried the fact for whoever asked and told
nobody.

- The condition store (to-be 45 §2): mesh-controller_conditions, one key
  per open condition, written by compare-and-set so a person's silence
  and the watchdogs never lose each other's word; every transition kept
  ninety days in mesh-controller_condition-history and said as the
  seat's events condition-raised / condition-changed / condition-cleared
  (the condition at the top level, with event, at, change, why, show),
  offered again while the bus is away. Raised and cleared by observation
  only; a clearing reopened within ten minutes is the same condition with
  its count up, its silence kept. Verbs: conditions, conditions show,
  conditions silence (a hand act, at most a week), conditions history.
- ADR 0224's provider standing is the first kind, provider-failing, held
  by the provider's events; the provider_standing table is no longer read
  or written (left in place: dropping it is the operator's word).
- status leads with the open conditions, urgent first, and says all well
  only with none open; conditions it cannot read are said and not well.
- The signals table compiled in, one watchdog loop over it every 30s: S1
  heartbeat (3 intervals, asleep machines excepted, control node urgent
  after 30 min), S2 report after a send, S3 plan tier, S4 event loop deaf,
  S5 merge not acted, S6 ask lost, S7 call hung, S8 provider silent, S9
  advisories, S10 self-check silent, S11 node tools silent, S13 stale
  refusals; S12, S14, S15 deferred with their reasons. A row that cannot
  see raises probe-failed and clears nothing. A test generated from the
  table suppresses each signal inside and past its bound.
- The bus's advisories (maximum deliveries, a mesh consumer deleted) and
  the controller's own slow consumer and refused subjects, said in the
  mesh's words.
- doctor: the probe registry D1-D10 (D5 deferred) and DW, every five
  minutes, each in thirty seconds; a probe that cannot run is never a
  pass. D1 validates with mesh-host's own validator. Every run ends with
  the doctor-heartbeat event mesh-watcher listens for.
- The controller is granted its new buckets, events, the two advisories
  and $SRV.INFO; the node tools their tools-alive heartbeat. The streams
  and consumers the controller asserts and the ones D6/D7 expect are one
  derivation.

internal/link/receive.go

@@ -25,11 +25,13 @@ import (
 // on the wire: the wire is the transport's business, and a kind that travelled would be a third
 // name for the same thing.
 const (
-	KindEnrolment   = "enrolment"
-	KindReport      = "report"
-	KindHeartbeat   = "heartbeat"
-	KindBuilt       = "built"
-	KindModuleMoved = "module-moved"
+	KindEnrolment = "enrolment"
+	KindReport    = "report"
+	KindHeartbeat = "heartbeat"
+	// KindToolsHeartbeat is a machine's node tools saying they are there (novox/hq to-be 45 S11).
+	KindToolsHeartbeat = "tools-heartbeat"
+	KindBuilt          = "built"
+	KindModuleMoved    = "module-moved"
 	// KindSourceMoved is the forge announcing a merge: a source moved, and what it produces is
 	// built without anybody telling the mesh (novox/hq 04-ISSUES/131).
 	KindSourceMoved = "source-moved"