feat: unify provider history context

src/config/config.test.ts

@@ -1225,6 +1225,34 @@ describe("legacy config detection", () => {
     }
   });
 
+  it("accepts historyLimit overrides per provider and account", async () => {
+    vi.resetModules();
+    const { validateConfigObject } = await import("./config.js");
+    const res = validateConfigObject({
+      messages: { groupChat: { historyLimit: 12 } },
+      whatsapp: { historyLimit: 9, accounts: { work: { historyLimit: 4 } } },
+      telegram: { historyLimit: 8, accounts: { ops: { historyLimit: 3 } } },
+      slack: { historyLimit: 7, accounts: { ops: { historyLimit: 2 } } },
+      signal: { historyLimit: 6 },
+      imessage: { historyLimit: 5 },
+      msteams: { historyLimit: 4 },
+      discord: { historyLimit: 3 },
+    });
+    expect(res.ok).toBe(true);
+    if (res.ok) {
+      expect(res.config.whatsapp?.historyLimit).toBe(9);
+      expect(res.config.whatsapp?.accounts?.work?.historyLimit).toBe(4);
+      expect(res.config.telegram?.historyLimit).toBe(8);
+      expect(res.config.telegram?.accounts?.ops?.historyLimit).toBe(3);
+      expect(res.config.slack?.historyLimit).toBe(7);
+      expect(res.config.slack?.accounts?.ops?.historyLimit).toBe(2);
+      expect(res.config.signal?.historyLimit).toBe(6);
+      expect(res.config.imessage?.historyLimit).toBe(5);
+      expect(res.config.msteams?.historyLimit).toBe(4);
+      expect(res.config.discord?.historyLimit).toBe(3);
+    }
+  });
+
   it('rejects imessage.dmPolicy="open" without allowFrom "*"', async () => {
     vi.resetModules();
     const { validateConfigObject } = await import("./config.js");