diff --git a/src/db.test.ts b/src/db.test.ts
index 10d880f..ccc42b9 100644
--- a/src/db.test.ts
+++ b/src/db.test.ts
@@ -35,7 +35,6 @@ import {
   getPairedTaskById,
   getPairedWorkspace,
   getRouterStateForService,
-  isPairedRoomJid,
   getSession,
   getTaskById,
   listPairedWorkspacesForTask,
@@ -796,7 +795,7 @@ describe('paired room registration', () => {
     ]);
     expect(getExplicitRoomMode('dc:123')).toBeUndefined();
     expect(getEffectiveRoomMode('dc:123')).toBe('tribunal');
-    expect(isPairedRoomJid('dc:123')).toBe(true);
+    expect(getEffectiveRuntimeRoomMode('dc:123')).toBe('tribunal');
   });
 
   it('does not mark solo rooms as paired', () => {
@@ -809,7 +808,7 @@ describe('paired room registration', () => {
     });
 
     expect(getRegisteredAgentTypesForJid('dc:solo')).toEqual(['claude-code']);
-    expect(isPairedRoomJid('dc:solo')).toBe(false);
+    expect(getEffectiveRuntimeRoomMode('dc:solo')).toBe('single');
   });
 
   it('keeps inferred room mode available when no explicit override exists', () => {
@@ -831,7 +830,6 @@ describe('paired room registration', () => {
     expect(getExplicitRoomMode('dc:legacy-paired')).toBeUndefined();
     expect(getEffectiveRoomMode('dc:legacy-paired')).toBe('tribunal');
     expect(getEffectiveRuntimeRoomMode('dc:legacy-paired')).toBe('tribunal');
-    expect(isPairedRoomJid('dc:legacy-paired')).toBe(true);
   });
 
   it('backfills inferred room modes for legacy SQL rows missing room_settings', () => {
@@ -899,7 +897,6 @@ describe('paired room registration', () => {
     expect(getExplicitRoomMode('dc:legacy-sql')).toBeUndefined();
     expect(getEffectiveRoomMode('dc:legacy-sql')).toBe('tribunal');
     expect(getEffectiveRuntimeRoomMode('dc:legacy-sql')).toBe('tribunal');
-    expect(isPairedRoomJid('dc:legacy-sql')).toBe(true);
   });
 
   it('lets explicit single override dual registration for paired-room checks', () => {
@@ -923,7 +920,6 @@ describe('paired room registration', () => {
     expect(getExplicitRoomMode('dc:explicit-single')).toBe('single');
     expect(getEffectiveRoomMode('dc:explicit-single')).toBe('single');
     expect(getEffectiveRuntimeRoomMode('dc:explicit-single')).toBe('single');
-    expect(isPairedRoomJid('dc:explicit-single')).toBe(false);
   });
 
   it('lets explicit tribunal become runnable when the configured reviewer can run on the solo registration', () => {
@@ -944,14 +940,12 @@ describe('paired room registration', () => {
     expect(getEffectiveRuntimeRoomMode('dc:explicit-tribunal')).toBe(
       'tribunal',
     );
-    expect(isPairedRoomJid('dc:explicit-tribunal')).toBe(true);
 
     clearExplicitRoomMode('dc:explicit-tribunal');
 
     expect(getExplicitRoomMode('dc:explicit-tribunal')).toBeUndefined();
     expect(getEffectiveRoomMode('dc:explicit-tribunal')).toBe('single');
     expect(getEffectiveRuntimeRoomMode('dc:explicit-tribunal')).toBe('single');
-    expect(isPairedRoomJid('dc:explicit-tribunal')).toBe(false);
   });
 
   it('keeps explicit tribunal non-runnable when the configured reviewer service is unavailable', () => {
@@ -969,7 +963,6 @@ describe('paired room registration', () => {
     expect(getEffectiveRuntimeRoomMode('dc:explicit-tribunal-codex')).toBe(
       'single',
     );
-    expect(isPairedRoomJid('dc:explicit-tribunal-codex')).toBe(false);
   });
 });
 
diff --git a/src/db.ts b/src/db.ts
index 1cfd03a..d389576 100644
--- a/src/db.ts
+++ b/src/db.ts
@@ -1974,7 +1974,12 @@ export function inferRoomModeFromRegisteredAgentTypes(
   return types.has('claude-code') && types.has('codex') ? 'tribunal' : 'single';
 }
 
-export function inferRoomModeForJid(jid: string): RoomMode {
+/**
+ * Internal registration/backfill helper.
+ * This infers the stored room mode from current registrations and must not be
+ * treated as runtime source-of-truth by callers.
+ */
+function inferStoredRoomModeForJid(jid: string): RoomMode {
   return inferRoomModeFromRegisteredAgentTypes(
     getRegisteredAgentTypesForJid(jid),
   );
@@ -2022,7 +2027,7 @@ function upsertStoredRoomMode(
 }
 
 function syncInferredRoomModeForJid(chatJid: string): void {
-  upsertStoredRoomMode(chatJid, inferRoomModeForJid(chatJid), 'inferred');
+  upsertStoredRoomMode(chatJid, inferStoredRoomModeForJid(chatJid), 'inferred');
 }
 
 export function getExplicitRoomMode(chatJid: string): RoomMode | undefined {
@@ -2070,10 +2075,6 @@ export function getEffectiveRuntimeRoomMode(chatJid: string): RoomMode {
     : 'single';
 }
 
-export function isPairedRoomJid(jid: string): boolean {
-  return getEffectiveRuntimeRoomMode(jid) === 'tribunal';
-}
-
 function backfillStoredRoomModes(database: Database): void {
   const rows = database
     .prepare(
diff --git a/src/duplicate-suppression.test.ts b/src/duplicate-suppression.test.ts
index 3fe2379..af938af 100644
--- a/src/duplicate-suppression.test.ts
+++ b/src/duplicate-suppression.test.ts
@@ -7,11 +7,11 @@ import {
   createProducedWorkItem,
   getOpenWorkItem,
   setRegisteredGroup,
-  isPairedRoomJid,
   getLastBotFinalMessage,
   markWorkItemDelivered,
 } from './db.js';
 import { normalizeMessageForDedupe } from './router.js';
+import { hasReviewerLease } from './service-routing.js';
 import { isDuplicateOfLastBotFinal } from './message-runtime.js';
 
 beforeEach(() => {
@@ -52,7 +52,7 @@ const setupChat = (jid: string) => {
   );
 };
 
-describe('isPairedRoomJid', () => {
+describe('hasReviewerLease', () => {
   it('returns true when both claude-code and codex are registered', () => {
     const jid = 'dc:paired-room';
 
@@ -72,7 +72,7 @@ describe('isPairedRoomJid', () => {
       agentType: 'codex',
     });
 
-    expect(isPairedRoomJid(jid)).toBe(true);
+    expect(hasReviewerLease(jid)).toBe(true);
   });
 
   it('returns false when only claude-code is registered', () => {
@@ -86,7 +86,7 @@ describe('isPairedRoomJid', () => {
       agentType: 'claude-code',
     });
 
-    expect(isPairedRoomJid(jid)).toBe(false);
+    expect(hasReviewerLease(jid)).toBe(false);
   });
 
   it('returns false when only codex is registered', () => {
@@ -100,7 +100,7 @@ describe('isPairedRoomJid', () => {
       agentType: 'codex',
     });
 
-    expect(isPairedRoomJid(jid)).toBe(false);
+    expect(hasReviewerLease(jid)).toBe(false);
   });
 });
 
@@ -209,7 +209,7 @@ describe('isDuplicateOfLastBotFinal (runtime function)', () => {
     );
 
     // Verify it's a paired room
-    expect(isPairedRoomJid(jid)).toBe(true);
+    expect(hasReviewerLease(jid)).toBe(true);
 
     // Verify duplicate detection works via the actual runtime function
     expect(
@@ -246,7 +246,7 @@ describe('isDuplicateOfLastBotFinal (runtime function)', () => {
     );
 
     // Verify it's NOT a paired room
-    expect(isPairedRoomJid(jid)).toBe(false);
+    expect(hasReviewerLease(jid)).toBe(false);
 
     // Duplicate check should be bypassed (return false)
     expect(isDuplicateOfLastBotFinal(jid, 'DONE — Task completed')).toBe(false);