Merge commit '4383844' into overnight-jul31

# Conflicts:
#	deploy/mavend.json
#	internal/config/config.go

internal/config/config.go

@@ -284,6 +284,14 @@ type VoiceConfig struct {
 	// default if unset.
 	QueryMinScore float64 `json:"query_min_score,omitempty"`
 
+	// QueryMinMargin — the second half of the recall gate: the top hit must
+	// beat the runner-up by more than this. The absolute score above cannot do
+	// the job on its own, because the e5 embedder puts every cosine in one
+	// narrow high band, so a made-up question scores as high as a real one.
+	// The margin asks whether one note is clearly the best instead.
+	// Negative ⇒ off. 0 ⇒ the default below.
+	QueryMinMargin float64 `json:"query_min_margin,omitempty"`
+
 	// Persona — optional prompt prefix that tunes maven's character. Prepended
 	// to every LLM system prompt (nudge phrasing, note queries, general
 	// knowledge). Empty string ⇒ current hardcoded persona (feminine-gendered
@@ -411,7 +419,12 @@ const (
 	DefaultAutotuneInterval = 10 * time.Minute
 	DefaultRouterThreshold  = 0.55
 	DefaultQueryMinScore    = 0.55
-	DefaultToolTimeout      = 30 * time.Second
+	// Read off the margin sweep in internal/memory/recalleval on the e5
+	// embedder: 0.008 answers 68% of real questions (down from 72%) and cuts
+	// false recall from 5/5 to 1/5. Every larger delta costs real recall
+	// without removing that last one until 0.020, which drops recall to 44%.
+	DefaultQueryMinMargin = 0.008
+	DefaultToolTimeout    = 30 * time.Second
 	// DefaultLLMRouter — route with the resident model unless told otherwise.
 	DefaultLLMRouter = true
 
@@ -495,6 +508,14 @@ func (c *Config) applyDefaults() {
 		if c.Voice.QueryMinScore <= 0 {
 			c.Voice.QueryMinScore = DefaultQueryMinScore
 		}
+		// Unset ⇒ default. Negative is how you turn the margin off on purpose,
+		// so it is clamped to 0 rather than replaced by the default.
+		switch {
+		case c.Voice.QueryMinMargin == 0:
+			c.Voice.QueryMinMargin = DefaultQueryMinMargin
+		case c.Voice.QueryMinMargin < 0:
+			c.Voice.QueryMinMargin = 0
+		}
 		if c.Voice.ToolTimeout <= 0 {
 			c.Voice.ToolTimeout = Duration(DefaultToolTimeout)
 		}