sweep claim, decision, netscan and vision (V-581)

The decision ring kept evicted turn records reachable. Push resliced the
backing array forward without clearing the dropped pointers, so up to
ringSize records stayed addressable until the next append reallocated. The
package holds this store in memory precisely so his words do not outlive the
diagnosis, and the reslice quietly broke that. Push now nils the dropped
slots first.

internal/claim carried three drifted counts in its package doc. The cascade
has twenty-two stage-0 grammars and not ten, and seven stateful pre-emptors
and not four. The band ordering itself did not drift: bandOf still maps stage
0 to anchored, the LLM router to structural and the classifier to nearest,
which is the order buildRouter and querySources actually run in.
BandStructural now names preRouteLadder as the roster so the next count is
checkable rather than remembered.

netscan formatted a port with fmt.Sprintf once per probe. A default scan is
1016 probes, so strconv.Itoa is the same string for less work, and the local
itoa helper goes with it.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

internal/claim/claim.go

@@ -2,8 +2,8 @@
 // utterance (V-565, umbrella V-558, design in
 // docs/plans/19-dialogue-arbitration.md).
 //
-// Maven's cascade has roughly ten stage-0 grammars, seven router intents,
-// twenty-two query sources and four stateful pre-emptors, and every one of them
+// Maven's cascade has twenty-two stage-0 grammars, seven router intents,
+// twenty-two query sources and seven stateful pre-emptors, and every one of them
 // answers "is this mine?" alone. None can answer "is this more mine than
 // yours?", because their scores are not comparable: stage 0 asserts 1.0 by
 // fiat, the classifier reports a cosine, the LLM router derives one from
@@ -56,8 +56,9 @@ const (
 	// BandStructural — the claimant read the whole sentence and produced a
 	// complete route, every slot its intent requires filled. The LLM router at
 	// full confidence, and a stateful claimant holding a pending question.
-	// Below BandAnchored on purpose: the four stateful claimants pre-empt
-	// unconditionally today, and that is the V-558 defect.
+	// Below BandAnchored on purpose: the stateful claimants pre-empt
+	// unconditionally today, and that is the V-558 defect. There are seven of
+	// them and preRouteLadder in cmd/mavend/decisiontrace.go is the roster.
 	BandStructural
 
 	// BandAnchored — a literal pattern anchored in the utterance matched, and