feat: centralize send message production gate

docs/current-status-card.md

@@ -58,7 +58,7 @@ N13/N14/N15 are pre-business validation results. They can help identify UI eleme
 
 ## Current loop
 
-Current loop: `R6g send audit and idempotency replay diagnostics complete; next R6h central production gate policy for send message`.
+Current loop: `R6h central production gate policy for send message complete; next R6i B-route connector adapter shell`.
 
 Active continuous execution plan: `docs/superpowers/plans/2026-07-10-r6f-r14-continuous-execution-plan.md`.
 
@@ -239,8 +239,8 @@ Continuous execution plan R6f-R14 is approved and execution has started:
 - Plan file: `docs/superpowers/plans/2026-07-10-r6f-r14-continuous-execution-plan.md`.
 - Scope: 15 ordered rounds covering send-message connector/gate hardening, send-file preview/idempotency/package, receive-file download preview, receive-message reconciliation, end-to-end business smoke, and release-candidate report.
 - Execution rule after approval: one round at a time, status-card update, verification, commit, push, then continue automatically until an evidence-only blocker requires user action.
-- Last completed round: R6g send audit and idempotency replay diagnostics.
+- Last completed round: R6h central production gate policy for send message.
-- Next active round: R6h central production gate policy for send message.
+- Next active round: R6i B-route connector adapter shell.
 
 R6g send audit and idempotency replay diagnostics is complete:
 
@@ -250,3 +250,12 @@ R6g send audit and idempotency replay diagnostics is complete:
 - Added `TestISphereSendMessageAuditRedactionIsStable` proving file-backed audit JSONL does not store raw message body or raw idempotency key.
 - Standard verification still reports 9 tools and `production_send_enabled=false`.
 - Next node: R6h central production gate policy for send message.
+
+R6h central production gate policy for send message is complete:
+
+- Added `SendMessageGatePolicy` and `LoadSendMessageGatePolicy`.
+- Gate reason codes are now explicit: `send_disabled_by_default`, `send_evidence_missing`, `send_connector_missing`, and `send_gate_passed`.
+- Default production-blocked `isphere_send_message` responses and audit events include `gate_reason_code` and `gate_reason_message`.
+- `ISPHERE_SEND_PRODUCTION_ENABLED=1` is recognized by policy tests, but it is not enough by itself; evidence and connector gates must also pass.
+- Standard verification still reports 9 tools and `production_send_enabled=false`.
+- Next node: R6i B-route connector adapter shell.

docs/go-mcp-runbook.md

@@ -285,6 +285,15 @@ powershell -NoProfile -ExecutionPolicy Bypass -File scripts\verify-send-audit-id
 
 The diagnostic prints sanitized counts and booleans: `audit_records`, `idempotency_records`, `duplicate_detected`, `conflict_detected`, `raw_body_present`, and `raw_idempotency_key_present`. It exits non-zero if a raw message body field or raw idempotency-key field is found.
 
+R6h centralizes the production-send gate. Default `execution_mode="production"` responses include machine-readable `gate_reason_code` and `gate_reason_message`. The valid gate codes are:
+
+- `send_disabled_by_default`
+- `send_evidence_missing`
+- `send_connector_missing`
+- `send_gate_passed`
+
+`ISPHERE_SEND_PRODUCTION_ENABLED=1` is recognized by the gate policy, but it is not sufficient by itself: the evidence gate and connector gate must also pass before production can be allowed. In the default MCP server path, `production_send_enabled` remains `false`.
+
 ## 10. Current tool surface and next-stage route
 
 The current runbook verifies nine tools:

docs/superpowers/plans/2026-07-10-r6f-r14-continuous-execution-plan.md

@@ -239,7 +239,7 @@ git push gitea main
 - Produces: `LoadSendMessageGatePolicy(env map[string]string, evidenceGatePass bool, connectorConfigured bool) SendMessageGatePolicy`.
 - Valid reason codes: `send_evidence_missing`, `send_connector_missing`, `send_disabled_by_default`, `send_gate_passed`.
 
-- [ ] **Step 1: Write table tests**
+- [x] **Step 1: Write table tests**
 
 Create `TestLoadSendMessageGatePolicy` with cases for default disabled, env set but evidence missing, evidence pass but connector missing, and all pass.
 
@@ -249,15 +249,15 @@ go test ./internal/tools -run TestLoadSendMessageGatePolicy -v
 
 Expected before implementation: FAIL because the gate type does not exist.
 
-- [ ] **Step 2: Implement gate policy**
+- [x] **Step 2: Implement gate policy**
 
 Create `send_message_gate.go` with the exact type/function and reason-code order from the test.
 
-- [ ] **Step 3: Route blocked production through the gate**
+- [x] **Step 3: Route blocked production through the gate**
 
 Modify `isphere_send_message.go` so blocked production responses include `gate_reason_code` and `gate_reason_message` from `SendMessageGatePolicy`.
 
-- [ ] **Step 4: Verify and commit**
+- [x] **Step 4: Verify and commit**
 
 ```powershell
 git diff --check
@@ -272,6 +272,13 @@ git push gitea main
 
 **Acceptance gate:** The default runtime stays blocked, but the response explains the exact reason in machine-readable fields.
 
+**R6h Result:**
+
+- Added `internal/tools/send_message_gate.go` with `SendMessageGatePolicy` and `LoadSendMessageGatePolicy`.
+- Added table tests for `send_disabled_by_default`, `send_evidence_missing`, `send_connector_missing`, and `send_gate_passed`.
+- Default `isphere_send_message` production-blocked responses and audit events now include `gate_reason_code` and `gate_reason_message`.
+- `ISPHERE_SEND_PRODUCTION_ENABLED=1` is recognized by policy tests, but the default MCP runtime still has no real connector and reports `production_send_enabled=false`.
+
 ---
 
 ### R6i: B-route connector adapter shell

internal/tools/isphere_send_message.go

@@ -61,6 +61,8 @@ type SendMessageAuditEvent struct {
 	AckRef               string         `json:"ack_ref,omitempty"`
 	ErrorCode            string         `json:"error_code,omitempty"`
 	ErrorMessage         string         `json:"error_message,omitempty"`
+	GateReasonCode       string         `json:"gate_reason_code,omitempty"`
+	GateReasonMessage    string         `json:"gate_reason_message,omitempty"`
 	AuditRef             string         `json:"audit_ref"`
 	StartedAt            string         `json:"started_at"`
 	FinishedAt           string         `json:"finished_at"`
@@ -130,7 +132,8 @@ func RegisterISphereSendMessageToolWithStateAndConnector(server *mcp.Server, aud
 			return nil, nil, err
 		}
 		finished := time.Now().UTC()
-		response, event := sendMessagePreviewResponse(normalized, started, finished, connector != nil)
+		gatePolicy := currentSendMessageGatePolicy(connector != nil)
+		response, event := sendMessagePreviewResponse(normalized, started, finished, connector != nil, gatePolicy)
 		decision, err := idempotencyStore.ReserveSendMessageIdempotency(ctx, sendMessageIdempotencyRecordFromAuditEvent(event))
 		if err != nil {
 			return nil, nil, fmt.Errorf("%s idempotency reserve failed: %w", ToolNameSendMessage, err)
@@ -161,6 +164,12 @@ func defaultSendMessageIdempotencyStore() SendMessageIdempotencyStore {
 	return fileSendMessageIdempotencyStore{path: filepath.Join("runs", "send-audit", "send-message-idempotency.jsonl")}
 }
 
+func currentSendMessageGatePolicy(connectorConfigured bool) SendMessageGatePolicy {
+	return LoadSendMessageGatePolicy(map[string]string{
+		EnvSendMessageProductionEnabled: os.Getenv(EnvSendMessageProductionEnabled),
+	}, false, connectorConfigured)
+}
+
 func (s fileSendMessageAuditSink) AppendSendMessageAudit(_ context.Context, event SendMessageAuditEvent) error {
 	if strings.TrimSpace(s.path) == "" {
 		return nil
@@ -343,12 +352,14 @@ func normalizeSendMessageExecutionMode(value string) (string, error) {
 	}
 }
 
-func sendMessagePreviewResponse(input normalizedSendMessageArgs, started time.Time, finished time.Time, connectorAvailable bool) (map[string]any, SendMessageAuditEvent) {
+func sendMessagePreviewResponse(input normalizedSendMessageArgs, started time.Time, finished time.Time, connectorAvailable bool, gatePolicy SendMessageGatePolicy) (map[string]any, SendMessageAuditEvent) {
 	sideEffects := sendMessageNoSideEffects()
 	status := "planned"
 	stage := sendMessagePreviewStage
 	ok := true
 	blockedReason := any(nil)
+	gateReasonCode := ""
+	gateReasonMessage := ""
 	if input.ExecutionMode == sendMessageProductionMode {
 		if connectorAvailable {
 			stage = sendMessagePreviewStage
@@ -356,7 +367,9 @@ func sendMessagePreviewResponse(input normalizedSendMessageArgs, started time.Ti
 			ok = false
 			status = "blocked"
 			stage = sendMessageBlockedStage
-			blockedReason = "production send is blocked until dynamic observation, idempotency audit, and one approved sandbox send gate pass"
+			gateReasonCode = gatePolicy.ReasonCode
+			gateReasonMessage = gatePolicy.ReasonMessage
+			blockedReason = gateReasonMessage
 		}
 	}
 	auditRef := sendMessageAuditRef(input.ContentSHA256, input.IdempotencyKeySHA256)
@@ -374,6 +387,8 @@ func sendMessagePreviewResponse(input normalizedSendMessageArgs, started time.Ti
 		IdempotencyKeySHA256: input.IdempotencyKeySHA256,
 		SendStatus:           status,
 		Result:               status,
+		GateReasonCode:       gateReasonCode,
+		GateReasonMessage:    gateReasonMessage,
 		AuditRef:             auditRef,
 		StartedAt:            started.Format(time.RFC3339Nano),
 		FinishedAt:           finished.Format(time.RFC3339Nano),
@@ -387,6 +402,8 @@ func sendMessagePreviewResponse(input normalizedSendMessageArgs, started time.Ti
 		"connector":               sendMessageConnector,
 		"connector_mode":          sendMessageConnectorMode,
 		"connector_stage":         stage,
+		"gate_reason_code":        gateReasonCode,
+		"gate_reason_message":     gateReasonMessage,
 		"production_send_enabled": false,
 		"target": map[string]any{
 			"target_type": input.TargetType,
@@ -406,18 +423,20 @@ func sendMessagePreviewResponse(input normalizedSendMessageArgs, started time.Ti
 		},
 		"side_effects": sideEffects,
 		"audit": map[string]any{
-			"tool":            ToolNameSendMessage,
+			"tool":                ToolNameSendMessage,
-			"source":          sendMessageConnector,
+			"source":              sendMessageConnector,
-			"execution_mode":  input.ExecutionMode,
+			"execution_mode":      input.ExecutionMode,
-			"connector":       sendMessageConnector,
+			"connector":           sendMessageConnector,
-			"connector_mode":  sendMessageConnectorMode,
+			"connector_mode":      sendMessageConnectorMode,
-			"connector_stage": stage,
+			"connector_stage":     stage,
-			"content_sha256":  input.ContentSHA256,
+			"gate_reason_code":    gateReasonCode,
-			"target_ref":      input.TargetRef,
+			"gate_reason_message": gateReasonMessage,
-			"audit_ref":       auditRef,
+			"content_sha256":      input.ContentSHA256,
-			"started_at":      started.Format(time.RFC3339Nano),
+			"target_ref":          input.TargetRef,
-			"finished_at":     finished.Format(time.RFC3339Nano),
+			"audit_ref":           auditRef,
-			"result":          status,
+			"started_at":          started.Format(time.RFC3339Nano),
+			"finished_at":         finished.Format(time.RFC3339Nano),
+			"result":              status,
 		},
 	}
 	return response, event

internal/tools/isphere_send_message_test.go

@@ -147,6 +147,47 @@ func TestISphereSendMessageProductionIsBlockedWithoutSideEffects(t *testing.T) {
 	}
 }
 
+func TestISphereSendMessageProductionBlockedIncludesGateReason(t *testing.T) {
+	audit := &fakeSendMessageAuditSink{}
+	session, cleanup := connectToolsTestSession(t, func(server *mcp.Server) {
+		RegisterISphereSendMessageToolWithState(server, audit, newFakeSendMessageIdempotencyStore())
+	})
+	defer cleanup()
+
+	content := "blocked gate reason"
+	callResult, err := session.CallTool(context.Background(), &mcp.CallToolParams{
+		Name: ToolNameSendMessage,
+		Arguments: map[string]any{
+			"target_type":     "direct",
+			"target_id":       "alice@imopenfire1-lanzhou",
+			"content_text":    content,
+			"content_sha256":  sha256HexForSendMessageTest(content),
+			"idempotency_key": "idem-gate-reason-1",
+			"execution_mode":  "production",
+		},
+	})
+	if err != nil {
+		t.Fatalf("call production blocked gate reason: %v", err)
+	}
+
+	var decoded struct {
+		OK                bool   `json:"ok"`
+		SendStatus        string `json:"send_status"`
+		GateReasonCode    string `json:"gate_reason_code"`
+		GateReasonMessage string `json:"gate_reason_message"`
+	}
+	payload, _ := json.Marshal(callResult.StructuredContent)
+	if err := json.Unmarshal(payload, &decoded); err != nil {
+		t.Fatalf("decode payload %s: %v", payload, err)
+	}
+	if decoded.OK || decoded.SendStatus != "blocked" || decoded.GateReasonCode != "send_disabled_by_default" || decoded.GateReasonMessage == "" {
+		t.Fatalf("production blocked response missing gate reason: %s", payload)
+	}
+	if len(audit.events) != 1 || audit.events[0].GateReasonCode != "send_disabled_by_default" || audit.events[0].GateReasonMessage == "" {
+		t.Fatalf("audit event missing gate reason: %+v", audit.events)
+	}
+}
+
 func TestISphereSendMessageFakeConnectorAcceptedAudit(t *testing.T) {
 	audit := &fakeSendMessageAuditSink{}
 	idempotency := newFakeSendMessageIdempotencyStore()

internal/tools/send_message_gate.go

@@ -0,0 +1,47 @@
+package tools
+
+import "strings"
+
+const EnvSendMessageProductionEnabled = "ISPHERE_SEND_PRODUCTION_ENABLED"
+
+type SendMessageGatePolicy struct {
+	ProductionAllowed   bool
+	ReasonCode          string
+	ReasonMessage       string
+	EvidenceGatePass    bool
+	ConnectorConfigured bool
+}
+
+func LoadSendMessageGatePolicy(env map[string]string, evidenceGatePass bool, connectorConfigured bool) SendMessageGatePolicy {
+	policy := SendMessageGatePolicy{
+		EvidenceGatePass:    evidenceGatePass,
+		ConnectorConfigured: connectorConfigured,
+	}
+	if !sendMessageProductionEnabled(env) {
+		policy.ReasonCode = "send_disabled_by_default"
+		policy.ReasonMessage = "production send is disabled by default; set ISPHERE_SEND_PRODUCTION_ENABLED=1 only after the evidence and connector gates pass"
+		return policy
+	}
+	if !evidenceGatePass {
+		policy.ReasonCode = "send_evidence_missing"
+		policy.ReasonMessage = "production send is blocked until dynamic observation, idempotency audit, and one approved sandbox send gate pass"
+		return policy
+	}
+	if !connectorConfigured {
+		policy.ReasonCode = "send_connector_missing"
+		policy.ReasonMessage = "production send is blocked because no validated send connector is configured"
+		return policy
+	}
+	policy.ProductionAllowed = true
+	policy.ReasonCode = "send_gate_passed"
+	policy.ReasonMessage = "production send gate passed"
+	return policy
+}
+
+func sendMessageProductionEnabled(env map[string]string) bool {
+	if env == nil {
+		return false
+	}
+	value := strings.TrimSpace(strings.ToLower(env[EnvSendMessageProductionEnabled]))
+	return value == "1" || value == "true" || value == "yes"
+}

internal/tools/send_message_gate_test.go

@@ -0,0 +1,33 @@
+package tools
+
+import "testing"
+
+func TestLoadSendMessageGatePolicy(t *testing.T) {
+	cases := []struct {
+		name        string
+		env         map[string]string
+		evidence    bool
+		connector   bool
+		wantAllowed bool
+		wantReason  string
+	}{
+		{name: "default disabled", env: map[string]string{}, evidence: false, connector: false, wantAllowed: false, wantReason: "send_disabled_by_default"},
+		{name: "env set but evidence missing", env: map[string]string{"ISPHERE_SEND_PRODUCTION_ENABLED": "1"}, evidence: false, connector: true, wantAllowed: false, wantReason: "send_evidence_missing"},
+		{name: "evidence pass but connector missing", env: map[string]string{"ISPHERE_SEND_PRODUCTION_ENABLED": "1"}, evidence: true, connector: false, wantAllowed: false, wantReason: "send_connector_missing"},
+		{name: "all pass", env: map[string]string{"ISPHERE_SEND_PRODUCTION_ENABLED": "1"}, evidence: true, connector: true, wantAllowed: true, wantReason: "send_gate_passed"},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			got := LoadSendMessageGatePolicy(tc.env, tc.evidence, tc.connector)
+			if got.ProductionAllowed != tc.wantAllowed || got.ReasonCode != tc.wantReason {
+				t.Fatalf("LoadSendMessageGatePolicy() = %+v, want allowed=%v reason=%q", got, tc.wantAllowed, tc.wantReason)
+			}
+			if got.ReasonMessage == "" {
+				t.Fatalf("ReasonMessage is empty for %+v", got)
+			}
+			if got.EvidenceGatePass != tc.evidence || got.ConnectorConfigured != tc.connector {
+				t.Fatalf("evidence/connector fields = %+v, want evidence=%v connector=%v", got, tc.evidence, tc.connector)
+			}
+		})
+	}
+}