Fixed CLI hanging when terminal is closed (#897)

## What was changed

- Added `SIGHUP` signal handling to gracefully exit when the terminal
disconnects
- Added broken pipe detection in the printer to exit cleanly instead of
hanging when stdout becomes unavailable

## Why?

When a user closes a terminal tab while the CLI is running (or an SSH
session drops), the CLI process could get stuck in an uninterruptible
state. This happened because:

1. The CLI wasn't listening for `SIGHUP` (the signal sent when a
terminal closes)
2. Writes to stdout would block forever when the terminal's file
descriptors were revoked

Now the CLI exits gracefully in both cases instead of requiring a
force-kill.

## Checklist

1. The bug fix discovered during development

2. How was this tested:
   - Ran CLI commands and closed the terminal tab mid-execution
- Verified the process exits cleanly instead of hanging in `UE`
(uninterruptible sleep) state

3. Any docs updates needed?
   - No

Author: moedash

.gitignore

@@ -11,3 +11,5 @@
 /.zed
 /.claude
 *~
+
+.DS_Store

internal/printer/printer.go

@@ -3,12 +3,15 @@ package printer
 import (
 	"encoding/base64"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
+	"os"
 	"reflect"
 	"slices"
 	"strconv"
 	"strings"
+	"syscall"
 	"time"
 
 	"github.com/fatih/color"
@@ -189,8 +192,25 @@ func (p *Printer) PrintStructuredTableIter(
 	}
 }
 
+// isBrokenPipeError returns true if the error indicates a broken pipe or
+// disconnected terminal (e.g., when the terminal is closed while writing).
+func isBrokenPipeError(err error) bool {
+	if errors.Is(err, syscall.EPIPE) {
+		return true
+	}
+	// Check for "broken pipe" in error message as a fallback
+	if err != nil && strings.Contains(err.Error(), "broken pipe") {
+		return true
+	}
+	return false
+}
+
 func (p *Printer) write(b []byte) {
 	if _, err := p.Output.Write(b); err != nil {
+		// Exit gracefully on broken pipe (terminal disconnected)
+		if isBrokenPipeError(err) {
+			os.Exit(0)
+		}
 		panic(err)
 	}
 }
@@ -201,6 +221,10 @@ func (p *Printer) writeStr(s string) {
 
 func (p *Printer) writef(s string, v ...any) {
 	if _, err := fmt.Fprintf(p.Output, s, v...); err != nil {
+		// Exit gracefully on broken pipe (terminal disconnected)
+		if isBrokenPipeError(err) {
+			os.Exit(0)
+		}
 		panic(err)
 	}
 }

internal/temporalcli/commands.go

@@ -108,7 +108,9 @@ func NewCommandContext(ctx context.Context, options CommandOptions) (*CommandCon
 	}
 
 	// Setup interrupt handler
-	ctx, stop := signal.NotifyContext(ctx, os.Interrupt, syscall.SIGTERM)
+	// Include SIGHUP to handle terminal disconnection gracefully
+	// Without this, the process may hang when the terminal is closed
+	ctx, stop := signal.NotifyContext(ctx, os.Interrupt, syscall.SIGTERM, syscall.SIGHUP)
 	cctx.Context = ctx
 	return cctx, stop, nil
 }