mavend: name the service that is down, and never read an empty list (V-521)

Two caller-side halves of the same review.

«экосистема недоступна» named nothing. Nexus, Praxis and Hexis fail
independently, and every one of the six call sites already knew which one it was
talking to — it writes that name into the trace on the line above. So eco_down
and eco_denied now take {name}, and he hears which service refused him.

The list entries are single-variant and placeholder-only, so an empty list has
no shorter wording to fall back on: attention_list would render as its own label
and a colon. Both Praxis readers checked the response length and neither checked
what survived formatting, so an item with no title counted toward a list it
could not appear in. They skip the untitled item and fall to the _none entry
when nothing is left.

The ecosystem tests asserted the substring "выполнена", which was a literal out
of the act file that review has now reworded. Seventeen sites go through actRan,
which asks the file.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XGTGCWX33aX8SMBSRz9VmS

cmd/mavend/ecosystem_acts.go

@@ -14,6 +14,19 @@ import (
 	"github.com/kami/maven/internal/store"
 )
 
+// The three services, spelled the way she says them out loud. A service that is
+// down or refusing has to be named: they degrade independently, so "не
+// отвечает" on its own tells him nothing he can act on, and each call site
+// already knows which one it was talking to — it records the same name in the
+// trace (Vikunja #521).
+const (
+	serviceNexus = "Nexus"
+	serviceHexis = "Hexis"
+)
+
+// serviceVars — the one-key map the eco_down and eco_denied lines take.
+func serviceVars(name string) map[string]string { return map[string]string{"name": name} }
+
 // praxisCapability is one arm of the Praxis act dispatch. This is an interface
 // rather than a map[string]func because each arm carries its own state: the
 // verb aliases it answers to, the trace name it records, and its own reply
@@ -158,6 +171,11 @@ func (listAttentionCapability) handle(ctx context.Context, h *reactiveHandler, p
 		importance, _ := item["importance"].(float64)
 		rule, _ := item["rule"].(string)
 		s := title
+		if s == "" {
+			// An item Praxis returned without a title is not an item she can
+			// read out. Counting it would put an empty slot in the list.
+			continue
+		}
 		if importance > 0 {
 			s += fmt.Sprintf(" (важность %d", int(importance))
 			if rule != "" {
@@ -176,6 +194,12 @@ func (listAttentionCapability) handle(ctx context.Context, h *reactiveHandler, p
 			}
 		}
 	}
+	if len(parts) == 0 {
+		// Praxis returned items and not one of them could be said. "ничего не
+		// требует внимания" is the honest answer; the list line would render as
+		// its own label and a colon (Vikunja #521).
+		return phraser.A(phraser.AttentionNone, nil)
+	}
 	return phraser.A(phraser.AttentionList, map[string]string{"items": strings.Join(parts, "; ")})
 }
 
@@ -202,9 +226,19 @@ func (listChangesCapability) handle(ctx context.Context, h *reactiveHandler, px
 	var parts []string
 	for _, c := range changes {
 		title, _ := c["title"].(string)
+		if title == "" {
+			continue
+		}
 		typ, _ := c["change_type"].(string)
+		if typ == "" {
+			parts = append(parts, title)
+			continue
+		}
 		parts = append(parts, fmt.Sprintf("%s (%s)", title, typ))
 	}
+	if len(parts) == 0 {
+		return phraser.A(phraser.ChangesNone, nil)
+	}
 	return phraser.A(phraser.ChangesList, map[string]string{"items": strings.Join(parts, "; ")})
 }
 
@@ -249,9 +283,9 @@ func (entityAttentionCapability) handle(ctx context.Context, h *reactiveHandler,
 		h.recordEcosystemTrace(ctx, "nexus", "resolve", traceStatusForError(err), started,
 			mergeFields(traceErrorFields(err), map[string]any{"subject": redactSubject(subject)}))
 		if unauthorizedEcosystemError(err) {
-			return phraser.A(phraser.EcoDenied, nil)
+			return phraser.A(phraser.EcoDenied, serviceVars(serviceNexus))
 		}
-		return phraser.A(phraser.EcoDown, nil)
+		return phraser.A(phraser.EcoDown, serviceVars(serviceNexus))
 	}
 	if len(ambiguous) > 0 {
 		return phraser.A(phraser.EcoAmbiguous, map[string]string{"items": strings.Join(ambiguous, ", ")})
@@ -521,13 +555,13 @@ func (h *reactiveHandler) handleHexisAct(ctx context.Context, dec router.Decisio
 		h.recordEcosystemTrace(ctx, "nexus", "resolve", traceStatusForError(err), started,
 			mergeFields(traceErrorFields(err), map[string]any{"subject": redactSubject(dec.Slots.Text)}))
 		if unauthorizedEcosystemError(err) {
-			return phraser.A(phraser.EcoDenied, nil)
+			return phraser.A(phraser.EcoDenied, serviceVars(serviceNexus))
 		}
 		// A genuine Nexus dependency failure, not "no such entity" — stop here
 		// and report degradation rather than silently falling through to the
 		// local command executor (ECOSYSTEM-SPEC.md: services degrade
 		// independently, never a silent all-clear).
-		return phraser.A(phraser.EcoDown, nil)
+		return phraser.A(phraser.EcoDown, serviceVars(serviceNexus))
 	}
 	if len(ambiguous) > 0 {
 		h.recordEcosystemTrace(ctx, "nexus", "resolve", traceAmbig, started,
@@ -551,9 +585,9 @@ func (h *reactiveHandler) handleHexisAct(ctx context.Context, dec router.Decisio
 		h.recordEcosystemTrace(ctx, "hexis", "capabilities", traceStatusForError(err), discovered,
 			mergeFields(traceErrorFields(err), map[string]any{"entity_id": entityID}))
 		if unauthorizedEcosystemError(err) {
-			return phraser.A(phraser.EcoDenied, nil)
+			return phraser.A(phraser.EcoDenied, serviceVars(serviceHexis))
 		}
-		return phraser.A(phraser.EcoDown, nil)
+		return phraser.A(phraser.EcoDown, serviceVars(serviceHexis))
 	}
 	h.recordEcosystemTrace(ctx, "hexis", "capabilities", traceOK, discovered,
 		map[string]any{"entity_id": entityID, "count": len(caps)})
@@ -603,7 +637,7 @@ func (h *reactiveHandler) handleHexisAct(ctx context.Context, dec router.Decisio
 		h.mu.Unlock()
 		h.recordEcosystemTrace(ctx, "hexis", "confirmation", tracePending, started,
 			map[string]any{"entity_id": entityID, "capability": matched.Name})
-		return phraser.A(phraser.ActConfirmEntity, map[string]string{"name": matched.Name, "entity": displayName})
+		return phraser.A(phraser.ActConfirmEntity, map[string]string{"name": matched.Name, "name_entity": displayName})
 	}
 
 	return h.execHexis(ctx, matched.ID, matched.Name, entityID, displayName)