Only a literal pattern may take the personal boundary off a turn (V-666)

Naming a destination takes the guessing query sources off a turn, and the
personal boundary is one of them. Every other guesser costs an answer when it
is wrongly dropped. This one costs the rule that a question about him never
reaches an upstream engine.

Three deciders name a destination now and two of them infer it: the routing
heads and the resident model. Decision.SourceAnchored says a stage 0 grammar
read the words instead. queryWalk honours it for the source marked
boundary: true and for no other, so the rest of the table is unchanged.

Owner's call of 2026-08-09.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013ptwopxyo3Z2kwFckHkLvN

internal/router/intent.go

@@ -111,6 +111,21 @@ type Decision struct {
 	// before this field existed. See source.go for why it is twelve values.
 	Source Source
 
+	// SourceAnchored — a stage 0 grammar named that destination, matching a
+	// literal pattern to do it. Only the router sets this, and only there.
+	//
+	// It exists because one thing downstream is not reversible by evidence
+	// (V-666). Naming a destination normally takes guessing sources off a turn,
+	// and one of those is the personal boundary, which is what stops a question
+	// about him from reaching the world. A grammar that read "что такое X" may
+	// take it off. A model or a softmax may not, because a wrong destination
+	// there widens what leaves the box rather than costing an answer.
+	//
+	// Read Stage instead and the two decisions get coupled: stage 0 also means
+	// confidence 1.0 and an anchored claim band, and a later cascade change
+	// could make one true where the other is not.
+	SourceAnchored bool
+
 	// Continued — this decision was rebuilt from the previous turn rather
 	// than routed, because the utterance was an ellipsis ("а завтра?").
 	// Handlers use it to know that Slots.Text is the PREVIOUS turn's topic

internal/router/router.go

@@ -98,6 +98,10 @@ func (r *Router) Route(ctx context.Context, utterance string, now time.Time) (De
 			continue // grammar matched shape but not content → fall through
 		}
 		d.Utterance = utterance
+		// A literal pattern named that destination, which is the one provenance
+		// allowed to take the personal boundary off a turn (V-666). Set here and
+		// nowhere else, so no other arm of the cascade can claim it.
+		d.SourceAnchored = d.Source != SourceUnknown
 		// The grammar decided the intent; the extractor fills the slots it did
 		// not match (V-572). See fillMatchedSlots for why every grammar gets it.
 		r.fillMatchedSlots(ctx, &d, now)