refactor: move WhatsApp group inference out of core

src/config/sessions.test.ts

@@ -107,7 +107,7 @@ describe("sessions", () => {
     {
       name: "returns normalized per-sender key",
       scope: "per-sender" as const,
-      ctx: { From: "whatsapp:+1555" },
+      ctx: { From: "chat:+1555" },
       expected: "+1555",
     },
     {
@@ -125,14 +125,14 @@ describe("sessions", () => {
     {
       name: "keeps group chats distinct",
       scope: "per-sender" as const,
-      ctx: { From: "12345-678@g.us", ChatType: "group", Provider: "whatsapp" },
-      expected: "whatsapp:group:12345-678@g.us",
+      ctx: { From: "room-123", ChatType: "group", Provider: "demo-chat" },
+      expected: "demo-chat:group:room-123",
     },
     {
       name: "prefixes group keys with provider when available",
       scope: "per-sender" as const,
-      ctx: { From: "12345-678@g.us", ChatType: "group", Provider: "whatsapp" },
-      expected: "whatsapp:group:12345-678@g.us",
+      ctx: { From: "room-456", ChatType: "group", Provider: "demo-chat" },
+      expected: "demo-chat:group:room-456",
     },
   ] as const;
 
@@ -179,7 +179,7 @@ describe("sessions", () => {
     {
       name: "maps direct chats to main key when provided",
       scope: "per-sender" as const,
-      ctx: { From: "whatsapp:+1555" },
+      ctx: { From: "chat:+1555" },
       mainKey: "main",
       expected: "agent:main:main",
     },
@@ -200,9 +200,9 @@ describe("sessions", () => {
     {
       name: "leaves groups untouched even with main key",
       scope: "per-sender" as const,
-      ctx: { From: "12345-678@g.us", ChatType: "group", Provider: "whatsapp" },
+      ctx: { From: "room-123", ChatType: "group", Provider: "demo-chat" },
       mainKey: "main",
-      expected: "agent:main:whatsapp:group:12345-678@g.us",
+      expected: "agent:main:demo-chat:group:room-123",
     },
   ] as const;
 
@@ -268,7 +268,7 @@ describe("sessions", () => {
     await updateLastRoute({
       storePath,
       sessionKey: mainSessionKey,
-      channel: "whatsapp",
+      channel: "demo-chat",
       to: "111",
       accountId: "legacy",
       deliveryContext: {
@@ -325,7 +325,7 @@ describe("sessions", () => {
   });
 
   it("updateLastRoute records origin + group metadata when ctx is provided", async () => {
-    const sessionKey = "agent:main:whatsapp:group:123@g.us";
+    const sessionKey = "agent:main:demo-chat:group:room-123";
     const { storePath } = await createSessionStoreFixture({
       prefix: "updateLastRoute",
       entries: {},
@@ -335,23 +335,23 @@ describe("sessions", () => {
       storePath,
       sessionKey,
       deliveryContext: {
-        channel: "whatsapp",
-        to: "123@g.us",
+        channel: "demo-chat",
+        to: "room-123",
       },
       ctx: {
-        Provider: "whatsapp",
+        Provider: "demo-chat",
         ChatType: "group",
         GroupSubject: "Family",
-        From: "123@g.us",
+        From: "room-123",
       },
     });
 
     const store = loadSessionStore(storePath);
     expect(store[sessionKey]?.subject).toBe("Family");
-    expect(store[sessionKey]?.channel).toBe("whatsapp");
-    expect(store[sessionKey]?.groupId).toBe("123@g.us");
-    expect(store[sessionKey]?.origin?.label).toBe("Family id:123@g.us");
-    expect(store[sessionKey]?.origin?.provider).toBe("whatsapp");
+    expect(store[sessionKey]?.channel).toBe("demo-chat");
+    expect(store[sessionKey]?.groupId).toBe("room-123");
+    expect(store[sessionKey]?.origin?.label).toBe("Family");
+    expect(store[sessionKey]?.origin?.provider).toBe("demo-chat");
     expect(store[sessionKey]?.origin?.chatType).toBe("group");
   });
 
@@ -461,18 +461,18 @@ describe("sessions", () => {
       store["agent:main:main"] = {
         sessionId: "sess-normalized",
         updatedAt: Date.now(),
-        lastChannel: " WhatsApp ",
+        lastChannel: " Demo Chat ",
         lastTo: " +1555 ",
         lastAccountId: " acct-1 ",
       };
     });
 
     const store = loadSessionStore(storePath);
-    expect(store["agent:main:main"]?.lastChannel).toBe("whatsapp");
+    expect(store["agent:main:main"]?.lastChannel).toBe("demo chat");
     expect(store["agent:main:main"]?.lastTo).toBe("+1555");
     expect(store["agent:main:main"]?.lastAccountId).toBe("acct-1");
     expect(store["agent:main:main"]?.deliveryContext).toEqual({
-      channel: "whatsapp",
+      channel: "demo chat",
       to: "+1555",
       accountId: "acct-1",
     });

src/config/sessions/group.ts

@@ -15,19 +15,6 @@ type LegacyGroupSessionSurface = {
   resolveLegacyGroupSessionKey?: (ctx: MsgContext) => GroupKeyResolution | null;
 };
 
-function resolveImplicitGroupSurface(params: {
-  from: string;
-  normalizedChatType?: "group" | "channel";
-}): { provider: string; chatType: "group" | "channel" } | null {
-  if (params.from.endsWith("@g.us")) {
-    return { provider: "whatsapp", chatType: "group" };
-  }
-  if (params.normalizedChatType) {
-    return null;
-  }
-  return null;
-}
-
 function resolveLegacyGroupSessionKey(ctx: MsgContext): GroupKeyResolution | null {
   for (const plugin of listChannelPlugins()) {
     const resolved = (
@@ -91,7 +78,6 @@ export function resolveGroupSessionKey(ctx: MsgContext): GroupKeyResolution | nu
   const chatType = normalizeOptionalLowercaseString(ctx.ChatType);
   const normalizedChatType =
     chatType === "channel" ? "channel" : chatType === "group" ? "group" : undefined;
-  const implicitGroupSurface = resolveImplicitGroupSurface({ from, normalizedChatType });
 
   const legacyResolution = resolveLegacyGroupSessionKey(ctx);
   const looksLikeGroup =
@@ -99,7 +85,6 @@ export function resolveGroupSessionKey(ctx: MsgContext): GroupKeyResolution | nu
     normalizedChatType === "channel" ||
     from.includes(":group:") ||
     from.includes(":channel:") ||
-    implicitGroupSurface !== null ||
     legacyResolution !== null;
   if (!looksLikeGroup) {
     return null;
@@ -115,9 +100,7 @@ export function resolveGroupSessionKey(ctx: MsgContext): GroupKeyResolution | nu
     return legacyResolution;
   }
 
-  const provider = headIsSurface
-    ? head
-    : (providerHint ?? implicitGroupSurface?.provider ?? legacyResolution?.channel);
+  const provider = headIsSurface ? head : (providerHint ?? legacyResolution?.channel);
   if (!provider) {
     return null;
   }
@@ -128,7 +111,7 @@ export function resolveGroupSessionKey(ctx: MsgContext): GroupKeyResolution | nu
     ? second
     : from.includes(":channel:") || normalizedChatType === "channel"
       ? "channel"
-      : (implicitGroupSurface?.chatType ?? "group");
+      : "group";
   const id = headIsSurface
     ? secondIsKind
       ? parts.slice(2).join(":")

src/secrets/channel-contract-surface-guardrails.test.ts

@@ -58,6 +58,10 @@ const CORE_SECRET_SURFACE_GUARDS = [
     path: "src/channels/model-overrides.ts",
     forbiddenPatterns: [/\bfeishu\b/],
   },
+  {
+    path: "src/config/sessions/group.ts",
+    forbiddenPatterns: [/\bwhatsapp\b/, /@g\.us/],
+  },
   {
     path: "src/media-understanding/defaults.ts",
     forbiddenPatterns: [