feat: add force resubscribe to ReadClient

src/app/ReadClient.cpp

@@ -930,6 +930,25 @@ CHIP_ERROR ReadClient::ProcessEventReportIBs(TLV::TLVReader & aEventReportIBsRea
     return err;
 }
 
+CHIP_ERROR ReadClient::ForceResubscribe()
+{
+    if (IsSubscriptionActive())
+    {
+        CancelLivenessCheckTimer();
+        OnLivenessTimeoutCallback(nullptr, this);
+        return CHIP_NO_ERROR;
+    }
+
+    if (IsIdle())
+    {
+        CancelResubscribeTimer();
+        OnResubscribeTimerCallback(nullptr, this);
+        return CHIP_NO_ERROR;
+    }
+
+    return CHIP_ERROR_INCORRECT_STATE;
+}
+
 void ReadClient::OverrideLivenessTimeout(System::Clock::Timeout aLivenessTimeout)
 {
     mLivenessTimeoutOverride = aLivenessTimeout;

src/app/ReadClient.h

@@ -503,6 +503,18 @@ class ReadClient : public Messaging::ExchangeDelegate
      */
     Optional<System::Clock::Timeout> GetSubscriptionTimeout();
 
+    /**
+     * Force the ReadClient to resubscribe immediately.
+     *
+     * This method can be called even when the subscription is active.
+     * It will simulate a liveness timeout to trigger the resubscription
+     * process according to the resubscription policy.
+     *
+     * @retval #CHIP_NO_ERROR On success.
+     * @retval #CHIP_ERROR_INCORRECT_STATE If the ReadClient is not in a state where resubscription is applicable.
+     */
+    CHIP_ERROR ForceResubscribe();
+
 private:
     friend class TestReadInteraction;
     friend class InteractionModelEngine;