fix: stratum deadlock + contrib-row CSS + README update for recent features

agent/miner/stratum.go

@@ -203,7 +203,10 @@ func (s *StratumClient) runPool(ep stratumEndpoint, stopCh <-chan struct{}) erro
 		}
 	})
 
-	// Submit writer goroutine.
+	// innerDone is closed when runPool returns for any reason (connection error
+	// or stopCh). It signals the submit goroutine to exit even when stopCh is
+	// still open, preventing a hang until the next share arrives.
+	innerDone := make(chan struct{})
 	submitDone := make(chan struct{})
 	go func() {
 		defer close(submitDone)
@@ -211,6 +214,8 @@ func (s *StratumClient) runPool(ep stratumEndpoint, stopCh <-chan struct{}) erro
 			select {
 			case <-stopCh:
 				return
+			case <-innerDone:
+				return
 			case share, ok := <-shareCh:
 				if !ok {
 					return
@@ -235,7 +240,22 @@ func (s *StratumClient) runPool(ep stratumEndpoint, stopCh <-chan struct{}) erro
 			}
 		}
 	}()
-	defer func() { <-submitDone }()
+	// Signal the submit goroutine and wait for it when runPool returns.
+	defer func() {
+		close(innerDone)
+		<-submitDone
+	}()
+
+	// Close the TCP connection as soon as stopCh fires so that the blocking
+	// reader.ReadString call (120 s deadline) unblocks immediately rather than
+	// making callers wait up to two minutes for the fallback to stop.
+	go func() {
+		select {
+		case <-stopCh:
+			_ = conn.Close()
+		case <-innerDone:
+		}
+	}()
 
 	// ── Job receive loop ──────────────────────────────────────────────────────
 	// keepalive every 60 s