router: introduce typed ActionValidationStatus boundary (slice 5)

Introduce ActionValidationStatus enum (valid, unresolved, missing_argument,
invalid_argument, ambiguous_target) as the typed classification of validation
outcomes. ActionValidationResult now carries Status instead of boolean flags.

Backward-compatible: Unresolved() and Valid() methods preserved on the result.
Existing validation behavior unchanged: only blank Fn produces invalid_argument.
All downstream behavior (proposeGap, confirmation, task_status, praxis, hexis)
unchanged.

Tests added for all five status values, backward compatibility, and the full
validation → execution boundary.

cmd/mavend/actionresolve.go

@@ -54,22 +54,23 @@ func noteActionResolution(ctx context.Context, source, fn string, resolved bool)
 }
 
 // noteActionValidation records the structural validation outcome in the
-// decision trace. Three outcomes: unresolved (matcher miss), valid
-// (structurally admissible), or invalid (structurally malformed).
+// decision trace. Five outcomes: unresolved (matcher miss), valid
+// (structurally admissible), invalid_argument, missing_argument, or
+// ambiguous_target (structurally malformed).
 func noteActionValidation(ctx context.Context, v router.ActionValidationResult) {
 	rec := decision.From(ctx)
 	if rec == nil {
 		return
 	}
-	switch {
-	case v.Unresolved:
+	switch v.Status {
+	case router.ActionUnresolved:
 		rec.Note(decision.Claim{
 			Stage:    decision.StageAction,
 			Claimant: "action-validation",
 			Outcome:  decision.Declined,
 			Reason:   "unresolved",
 		})
-	case v.Valid:
+	case router.ActionValid:
 		rec.Note(decision.Claim{
 			Stage:    decision.StageAction,
 			Claimant: "action-validation",
@@ -77,9 +78,9 @@ func noteActionValidation(ctx context.Context, v router.ActionValidationResult)
 			Reason:   "valid",
 		})
 	default:
-		reason := "invalid"
+		reason := string(v.Status)
 		if len(v.Issues) > 0 {
-			reason = "invalid:" + v.Issues[0].Reason
+			reason = string(v.Status) + ":" + v.Issues[0].Reason
 		}
 		rec.Note(decision.Claim{
 			Stage:    decision.StageAction,

cmd/mavend/actionresolve_test.go

@@ -385,3 +385,172 @@ func TestActExecutionFromCandidateNotSlots(t *testing.T) {
 		t.Errorf("execution from candidate replied %q; want tool success", reply)
 	}
 }
+
+// --- validation status boundary tests ---
+
+// TestActValidation_StatusValidRoute pins that a route-resolved valid action
+// produces ActionValid status and reaches execution.
+func TestActValidation_StatusValidRoute(t *testing.T) {
+	h, st := newActHandler(t)
+	ctx := context.Background()
+	now := h.now()
+
+	if err := st.EnableTool(ctx, "status", []string{"true"}, false, "test", now); err != nil {
+		t.Fatal(err)
+	}
+
+	reply := h.actionAct(ctx, router.Decision{
+		Intent:    router.IntentAct,
+		Utterance: "status",
+		Slots:     router.Slots{Fn: "status", HasFn: true},
+	})
+	if !strings.Contains(reply, "готово") {
+		t.Errorf("valid route act replied %q; want tool success", reply)
+	}
+}
+
+// TestActValidation_StatusValidMatcher pins that a matcher-resolved valid
+// action produces ActionValid status and reaches execution.
+func TestActValidation_StatusValidMatcher(t *testing.T) {
+	h, st := newActHandler(t)
+	ctx := context.Background()
+	now := h.now()
+
+	if err := st.EnableTool(ctx, "status", []string{"true"}, false, "test", now); err != nil {
+		t.Fatal(err)
+	}
+
+	reply := h.actionAct(ctx, router.Decision{
+		Intent:    router.IntentAct,
+		Utterance: "check status",
+		Slots:     router.Slots{Text: "status"},
+	})
+	if !strings.Contains(reply, "готово") {
+		t.Errorf("valid matcher act replied %q; want tool success", reply)
+	}
+}
+
+// TestActValidation_StatusUnresolved pins that an unresolved candidate
+// produces ActionUnresolved status and flows to proposeGap.
+func TestActValidation_StatusUnresolved(t *testing.T) {
+	h, st := newActHandler(t)
+	ctx := context.Background()
+	now := h.now()
+
+	if err := st.EnableTool(ctx, "status", []string{"true"}, false, "test", now); err != nil {
+		t.Fatal(err)
+	}
+
+	reply := h.actionAct(ctx, router.Decision{
+		Intent:    router.IntentAct,
+		Utterance: "deploy everything",
+		Slots:     router.Slots{Text: "deploy everything"},
+	})
+	if !strings.Contains(strings.ToLower(reply), "предлож") {
+		t.Errorf("unresolved act replied %q; want propose-gap", reply)
+	}
+}
+
+// TestActValidation_StatusInvalid pins that a structurally invalid candidate
+// produces ActionInvalidArgument status and refuses execution.
+func TestActValidation_StatusInvalid(t *testing.T) {
+	h, st := newActHandler(t)
+	ctx := context.Background()
+	now := h.now()
+
+	if err := st.EnableTool(ctx, "status", []string{"true"}, false, "test", now); err != nil {
+		t.Fatal(err)
+	}
+
+	reply := h.actionAct(ctx, router.Decision{
+		Intent:    router.IntentAct,
+		Utterance: "status",
+		Slots:     router.Slots{Fn: "  ", HasFn: true},
+	})
+	if reply == "" {
+		t.Error("expected a response for invalid candidate")
+	}
+	if strings.Contains(reply, "готово") {
+		t.Error("invalid candidate should not reach tool execution")
+	}
+}
+
+// TestActValidation_DestructiveValidStatus pins that a destructive but
+// structurally valid action still produces ActionValid status and reaches
+// the confirmation path (not validation failure).
+func TestActValidation_DestructiveValidStatus(t *testing.T) {
+	h, st := newActHandler(t)
+	ctx := context.Background()
+	now := h.now()
+
+	if err := st.EnableTool(ctx, "restart", []string{"true"}, true, "test", now); err != nil {
+		t.Fatal(err)
+	}
+
+	reply := h.actionAct(ctx, router.Decision{
+		Intent:    router.IntentAct,
+		Utterance: "restart",
+		Slots:     router.Slots{Fn: "restart", HasFn: true},
+	})
+	if !strings.Contains(reply, "да или нет") {
+		t.Errorf("destructive valid act replied %q; want confirm turn", reply)
+	}
+}
+
+// TestActValidation_ConfirmationUnchanged pins that the confirmation flow
+// is unchanged by validation.
+func TestActValidation_ConfirmationUnchanged(t *testing.T) {
+	h, st := newActHandler(t)
+	ctx := context.Background()
+	now := h.now()
+
+	if err := st.EnableTool(ctx, "restart", []string{"echo", "ok"}, true, "test", now); err != nil {
+		t.Fatal(err)
+	}
+
+	reply := h.actionAct(ctx, router.Decision{
+		Intent:    router.IntentAct,
+		Utterance: "restart nginx",
+		Slots:     router.Slots{Fn: "restart", Args: []string{"nginx"}, HasFn: true},
+	})
+	if !strings.Contains(reply, "да или нет") {
+		t.Errorf("confirmation act replied %q; want confirm turn", reply)
+	}
+}
+
+// TestActValidation_TaskStatusInterceptUnchanged pins that task_status
+// interception is unchanged by validation.
+func TestActValidation_TaskStatusInterceptUnchanged(t *testing.T) {
+	h, _ := newActHandler(t)
+	ctx := context.Background()
+
+	reply := h.actionAct(ctx, router.Decision{
+		Intent:    router.IntentAct,
+		Utterance: "task status",
+		Slots:     router.Slots{Fn: router.TaskStatusFn, HasFn: true, Text: "task status"},
+	})
+	if strings.Contains(reply, "готово") {
+		t.Errorf("task_status was not intercepted, got %q", reply)
+	}
+}
+
+// TestActValidation_NoExecutionOnFailure pins that validation failure
+// prevents downstream execution.
+func TestActValidation_NoExecutionOnFailure(t *testing.T) {
+	h, st := newActHandler(t)
+	ctx := context.Background()
+	now := h.now()
+
+	if err := st.EnableTool(ctx, "status", []string{"true"}, false, "test", now); err != nil {
+		t.Fatal(err)
+	}
+
+	reply := h.actionAct(ctx, router.Decision{
+		Intent:    router.IntentAct,
+		Utterance: "status",
+		Slots:     router.Slots{Fn: "   ", HasFn: true},
+	})
+	if strings.Contains(reply, "готово") {
+		t.Error("validation failure should not reach tool execution")
+	}
+}

cmd/mavend/actions_act.go

@@ -39,7 +39,7 @@ func (h *reactiveHandler) actionAct(ctx context.Context, dec router.Decision) st
 	validation := router.ValidateActionCandidate(candidate)
 	noteActionValidation(ctx, validation)
 
-	if !validation.Unresolved && !validation.Valid {
+	if !validation.Unresolved() && !validation.Valid() {
 		// Resolved but structurally malformed: refuse execution.
 		return phraser.A(phraser.ActFail, nil)
 	}

internal/router/actioncandidate.go

@@ -58,6 +58,38 @@ const (
 	FieldArgs ActionField = "args"
 )
 
+// ActionValidationStatus is the typed classification of a validation outcome.
+// Five disjoint values: exactly one is set on every ActionValidationResult.
+type ActionValidationStatus string
+
+const (
+	// ActionValid — Fn is non-empty and the candidate is structurally
+	// admissible. The caller may proceed to risk policy and execution.
+	ActionValid ActionValidationStatus = "valid"
+
+	// ActionUnresolved — Fn is empty. The matcher did not match, or the
+	// decision was not an act. The caller routes to proposeGap /
+	// clarification. This is NOT a structural error.
+	ActionUnresolved ActionValidationStatus = "unresolved"
+
+	// ActionMissingArgument — Fn is present but required arguments are
+	// absent. Currently unused: no tool declares required args at the
+	// candidate level. Preserved for future use without semantic change.
+	ActionMissingArgument ActionValidationStatus = "missing_argument"
+
+	// ActionInvalidArgument — Fn is present and arguments are present but
+	// structurally malformed (e.g. wrong shape for a known tool). Currently
+	// unused: argument shape is validated by the tool executor, not the
+	// candidate validator. Preserved for future use.
+	ActionInvalidArgument ActionValidationStatus = "invalid_argument"
+
+	// ActionAmbiguousTarget — Fn is present but the entity/target reference
+	// is ambiguous (multiple candidates, or a demonstrative with no
+	// referent). Currently handled downstream by ecosystem handlers, not
+	// the candidate validator. Preserved for future centralization.
+	ActionAmbiguousTarget ActionValidationStatus = "ambiguous_target"
+)
+
 // ActionValidationIssue records one structural problem found by
 // ValidateActionCandidate. Field names which field; Reason is a short
 // machine-readable tag, not a human sentence.
@@ -67,20 +99,26 @@ type ActionValidationIssue struct {
 }
 
 // ActionValidationResult is the typed output of ValidateActionCandidate.
-// Three disjoint outcomes:
+// Exactly one of the five Status values is set. Issues carries detail for
+// invalid statuses; it is nil for valid and unresolved.
 //
-//   - Unresolved: Fn is empty — the matcher did not match. The caller should
-//     route to proposeGap / clarification, not treat this as a structural error.
-//   - Valid: Fn is non-empty and the candidate is structurally admissible for
-//     the current execution path.
-//   - Invalid: Fn is non-empty but the candidate is structurally malformed.
-//     The caller should refuse execution.
+// The result answers only shape/completeness — not trust, confidence, risk,
+// or semantic correctness. Risk policy, confirmation, voice authority, and
+// irreversible-action policy remain downstream and unchanged.
 type ActionValidationResult struct {
-	Unresolved bool
-	Valid      bool
-	Issues     []ActionValidationIssue
+	Status  ActionValidationStatus
+	Issues  []ActionValidationIssue
+	Missing []string `json:"Missing,omitempty"`
 }
 
+// Unresolved reports whether the candidate was not resolved (Fn empty).
+// Kept as a method for backward compatibility with existing call sites.
+func (r ActionValidationResult) Unresolved() bool { return r.Status == ActionUnresolved }
+
+// Valid reports whether the candidate is structurally admissible.
+// Kept as a method for backward compatibility with existing call sites.
+func (r ActionValidationResult) Valid() bool { return r.Status == ActionValid }
+
 // ResolveActionCandidate produces an ActionCandidate from a routing decision.
 // It is the single boundary between routing and action resolution: everything
 // downstream consumes the candidate rather than re-resolving the function.
@@ -135,12 +173,17 @@ func ResolveActionCandidate(dec Decision, m ActMatcher) ActionCandidate {
 // structurally admissible for the current execution path. It answers only
 // shape/completeness — not trust, confidence, risk, or semantic correctness.
 //
-// Three outcomes:
+// Five outcomes (exactly one):
 //   - Unresolved (Fn empty): the matcher missed. Caller routes to
 //     proposeGap / clarification. This is NOT a validation error.
 //   - Valid (Fn non-empty, structure sound): candidate may proceed to
 //     risk policy and execution.
-//   - Invalid (Fn non-empty but malformed): candidate must not execute.
+//   - InvalidArgument (Fn present but args malformed): candidate must not
+//     execute. Currently unused; preserved for future use.
+//   - MissingArgument (Fn present but required args absent): candidate must
+//     not execute. Currently unused; preserved for future use.
+//   - AmbiguousTarget (Fn present but target ambiguous): candidate must not
+//     execute. Currently handled downstream; preserved for future use.
 //
 // Validation does not re-run routing, intent classification, matcher
 // resolution, language parsing, or entity inference.
@@ -149,7 +192,7 @@ func ValidateActionCandidate(c ActionCandidate) ActionValidationResult {
 	// was not an act. This flows into the existing propose-gap / proposal
 	// path and must NOT be treated as a structural error.
 	if c.Fn == "" {
-		return ActionValidationResult{Unresolved: true}
+		return ActionValidationResult{Status: ActionUnresolved}
 	}
 
 	var issues []ActionValidationIssue
@@ -165,7 +208,7 @@ func ValidateActionCandidate(c ActionCandidate) ActionValidationResult {
 	}
 
 	if len(issues) > 0 {
-		return ActionValidationResult{Issues: issues}
+		return ActionValidationResult{Status: ActionInvalidArgument, Issues: issues}
 	}
-	return ActionValidationResult{Valid: true}
+	return ActionValidationResult{Status: ActionValid}
 }

internal/router/actioncandidate_test.go

@@ -157,10 +157,10 @@ func TestResolveActionCandidate_AliasMatch(t *testing.T) {
 func TestValidateActionCandidate_UnresolvedEmptyFn(t *testing.T) {
 	c := ActionCandidate{}
 	v := ValidateActionCandidate(c)
-	if !v.Unresolved {
-		t.Error("expected unresolved for empty Fn")
+	if v.Status != ActionUnresolved {
+		t.Errorf("Status = %q, want unresolved", v.Status)
 	}
-	if v.Valid {
+	if v.Valid() {
 		t.Error("unresolved must not be valid")
 	}
 }
@@ -173,8 +173,8 @@ func TestValidateActionCandidate_UnresolvedMatcherMiss(t *testing.T) {
 		Confidence: 0.5,
 	}
 	v := ValidateActionCandidate(c)
-	if !v.Unresolved {
-		t.Error("expected unresolved for matcher miss")
+	if v.Status != ActionUnresolved {
+		t.Errorf("Status = %q, want unresolved", v.Status)
 	}
 }
 
@@ -187,11 +187,11 @@ func TestValidateActionCandidate_ValidRoute(t *testing.T) {
 		Source: ActionSourceRoute,
 	}
 	v := ValidateActionCandidate(c)
-	if v.Unresolved {
+	if v.Unresolved() {
 		t.Error("expected resolved, not unresolved")
 	}
-	if !v.Valid {
-		t.Errorf("expected valid, got issues: %v", v.Issues)
+	if v.Status != ActionValid {
+		t.Errorf("Status = %q, want valid; issues: %v", v.Status, v.Issues)
 	}
 }
 
@@ -203,11 +203,11 @@ func TestValidateActionCandidate_ValidMatcher(t *testing.T) {
 		Source: ActionSourceMatcher,
 	}
 	v := ValidateActionCandidate(c)
-	if v.Unresolved {
+	if v.Unresolved() {
 		t.Error("expected resolved, not unresolved")
 	}
-	if !v.Valid {
-		t.Errorf("expected valid, got issues: %v", v.Issues)
+	if v.Status != ActionValid {
+		t.Errorf("Status = %q, want valid; issues: %v", v.Status, v.Issues)
 	}
 }
 
@@ -218,11 +218,11 @@ func TestValidateActionCandidate_ValidNoArgs(t *testing.T) {
 		Source: ActionSourceRoute,
 	}
 	v := ValidateActionCandidate(c)
-	if v.Unresolved {
+	if v.Unresolved() {
 		t.Error("expected resolved, not unresolved")
 	}
-	if !v.Valid {
-		t.Errorf("expected valid, got issues: %v", v.Issues)
+	if v.Status != ActionValid {
+		t.Errorf("Status = %q, want valid; issues: %v", v.Status, v.Issues)
 	}
 }
 
@@ -234,12 +234,15 @@ func TestValidateActionCandidate_BlankFn(t *testing.T) {
 		Source: ActionSourceRoute,
 	}
 	v := ValidateActionCandidate(c)
-	if v.Unresolved {
+	if v.Unresolved() {
 		t.Error("blank Fn should be invalid, not unresolved")
 	}
-	if v.Valid {
+	if v.Valid() {
 		t.Error("blank Fn should be invalid")
 	}
+	if v.Status != ActionInvalidArgument {
+		t.Errorf("Status = %q, want invalid_argument", v.Status)
+	}
 	if len(v.Issues) != 1 {
 		t.Fatalf("expected 1 issue, got %d", len(v.Issues))
 	}
@@ -247,3 +250,105 @@ func TestValidateActionCandidate_BlankFn(t *testing.T) {
 		t.Errorf("issue field = %q, want fn", v.Issues[0].Field)
 	}
 }
+
+// --- additional typed status tests ---
+
+// TestValidateActionCandidate_StatusConstants pins that the five status
+// constants are distinct and non-empty.
+func TestValidateActionCandidate_StatusConstants(t *testing.T) {
+	statuses := []ActionValidationStatus{
+		ActionValid,
+		ActionUnresolved,
+		ActionMissingArgument,
+		ActionInvalidArgument,
+		ActionAmbiguousTarget,
+	}
+	seen := make(map[ActionValidationStatus]bool)
+	for _, s := range statuses {
+		if s == "" {
+			t.Error("status constant is empty")
+		}
+		if seen[s] {
+			t.Errorf("status %q appears twice", s)
+		}
+		seen[s] = true
+	}
+}
+
+// TestValidateActionCandidate_UnresolvedBackwardCompat pins that the
+// Unresolved() method returns true only for ActionUnresolved status.
+func TestValidateActionCandidate_UnresolvedBackwardCompat(t *testing.T) {
+	tests := []struct {
+		name   string
+		status ActionValidationStatus
+		want   bool
+	}{
+		{"unresolved", ActionUnresolved, true},
+		{"valid", ActionValid, false},
+		{"missing_arg", ActionMissingArgument, false},
+		{"invalid_arg", ActionInvalidArgument, false},
+		{"ambiguous", ActionAmbiguousTarget, false},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			r := ActionValidationResult{Status: tt.status}
+			if got := r.Unresolved(); got != tt.want {
+				t.Errorf("Unresolved() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+// TestValidateActionCandidate_ValidBackwardCompat pins that the Valid()
+// method returns true only for ActionValid status.
+func TestValidateActionCandidate_ValidBackwardCompat(t *testing.T) {
+	tests := []struct {
+		name   string
+		status ActionValidationStatus
+		want   bool
+	}{
+		{"unresolved", ActionUnresolved, false},
+		{"valid", ActionValid, true},
+		{"missing_arg", ActionMissingArgument, false},
+		{"invalid_arg", ActionInvalidArgument, false},
+		{"ambiguous", ActionAmbiguousTarget, false},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			r := ActionValidationResult{Status: tt.status}
+			if got := r.Valid(); got != tt.want {
+				t.Errorf("Valid() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+// TestValidateActionCandidate_IssuesNilOnValid pins that Valid results have
+// nil Issues.
+func TestValidateActionCandidate_IssuesNilOnValid(t *testing.T) {
+	c := ActionCandidate{Fn: "restart", Args: []string{"nginx"}}
+	v := ValidateActionCandidate(c)
+	if v.Issues != nil {
+		t.Errorf("valid result has issues: %v", v.Issues)
+	}
+}
+
+// TestValidateActionCandidate_IssuesNilOnUnresolved pins that Unresolved
+// results have nil Issues.
+func TestValidateActionCandidate_IssuesNilOnUnresolved(t *testing.T) {
+	c := ActionCandidate{}
+	v := ValidateActionCandidate(c)
+	if v.Issues != nil {
+		t.Errorf("unresolved result has issues: %v", v.Issues)
+	}
+}
+
+// TestValidateActionCandidate_IssuesPopulatedOnInvalid pins that Invalid
+// results carry populated Issues.
+func TestValidateActionCandidate_IssuesPopulatedOnInvalid(t *testing.T) {
+	c := ActionCandidate{Fn: "\t\n"}
+	v := ValidateActionCandidate(c)
+	if len(v.Issues) == 0 {
+		t.Error("invalid result has no issues")
+	}
+}