Look twice before saying a probe failed, and say conditions in machine names (hq issue 277)

D2 raised a resolver urgent on one query that timed out while its machine was
loaded, and its summary carried the resolver's address and socket text, so the
operator channel withheld the whole alert.

- D2 asks every question up to three times, all at once; a resolver that
  answers nothing is held for the next run and raised urgent when two runs
  in a row find it silent. A wrong answer is still raised at once.
- Findings a single look can be wrong about carry Confirm: raised on the
  second look in a row, kept while open, never cleared-and-reraised. Used by
  D2 silence, D3 (also asks discovery twice), D6 behind, D9, D13 unmeasured,
  probe-failed of the doctor, and blind watchdog rows.
- Probe seat asks (D8, D13) are asked again when the bus brought no answer.
- Summaries name machines and say things in words; addresses, paths,
  domains and raw errors move to the evidence (D2, D5, D8, D9, D13, S12).
- internal/outward mirrors the messenger's content rule, allowing the mesh's
  machine names; the keeper rewords a summary that would be withheld and keeps
  it whole in the evidence; a TestMain lint fails the suite on any raised or
  linted finding that would be withheld.

internal/conditions/condition.go

@@ -170,10 +170,19 @@ type Observation struct {
 	Also     []string
 	Severity Severity
 	Summary  string
-	// Said is this observation's evidence, in the mesh's words; Summary when empty.
+	// Said is this observation's evidence, in the mesh's words; Summary when empty. **Detail goes
+	// here, never in Summary**: an address, a socket's error, a path or a name with its domain is
+	// kept in the condition's evidence, which stays inside the mesh. The summary leaves it — to the
+	// operator's channel, whose content rule withholds a message that carries any of them (ADR 0234
+	// §6), and names machines in words.
 	Said     string
 	Source   string
 	Resolver string
+	// Confirm says a single look can be wrong about this finding — a question over the network that
+	// went unanswered, a time measured once on a loaded machine. The keeper does not read it: the
+	// source that looks again does, and raises it only when the next look sees it too, or while it is
+	// already open (novox/hq issue 277).
+	Confirm bool
 }
 
 // Key is where the observation's condition is kept: `<scope>.<id>.<kind>`, so the same fault said