refactor: move all app code to internal/termapp and entry to cmd/

Consolidate remaining package main files into internal/termapp for
clean separation: cmd/serialterminal/ is the sole entry point.
Update .goreleaser.yaml to build from ./cmd/serialterminal.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

.goreleaser.yaml

@@ -17,7 +17,8 @@ before:
 #    - go generate ./...
 
 builds:
-  - env:
+  - main: ./cmd/serialterminal
+    env:
       - CGO_ENABLED=0
     goos:
       - linux

cmd/serialterminal/main.go

@@ -0,0 +1,7 @@
+package main
+
+import "github.com/jixishi/SerialTerminalForWindowsTerminal/internal/termapp"
+
+func main() {
+	termapp.Run()
+}

internal/termapp/app.go

@@ -1,4 +1,4 @@
-package main
+package termapp
 
 import (
 	"bytes"

internal/termapp/app_test.go

@@ -1,4 +1,4 @@
-package main
+package termapp
 
 import (
 	"io"

internal/termapp/command.go

@@ -1,4 +1,4 @@
-package main
+package termapp
 
 import (
 	"encoding/hex"

internal/termapp/command_test.go

@@ -1,4 +1,4 @@
-package main
+package termapp
 
 import (
 	"io"

internal/termapp/config.go

@@ -1,4 +1,4 @@
-package main
+package termapp
 
 import (
 	appconfig "github.com/jixishi/SerialTerminalForWindowsTerminal/internal/config"

internal/termapp/config_test.go

@@ -1,4 +1,4 @@
-package main
+package termapp
 
 import (
 	"path/filepath"

internal/termapp/escape_test.go

@@ -1,4 +1,4 @@
-package main
+package termapp
 
 import (
 	"testing"

internal/termapp/main.go

@@ -1,4 +1,4 @@
-package main
+package termapp
 
 import (
 	"fmt"
@@ -21,7 +21,7 @@ func init() {
 	flag.Init(cfg)
 }
 
-func main() {
+func Run() {
 	defer func() {
 		if r := recover(); r != nil {
 			fmt.Fprintf(os.Stderr, "fatal: %v\n", r)

internal/termapp/main_other.go

@@ -1,5 +1,5 @@
 //go:build !windows
 
-package main
+package termapp
 
 func enableVTInput(fd int) {}

internal/termapp/main_windows.go

@@ -1,6 +1,6 @@
 //go:build windows
 
-package main
+package termapp
 
 import (
 	"golang.org/x/sys/windows"

internal/termapp/mutual.go

@@ -1,4 +1,4 @@
-package main
+package termapp
 
 import (
 	"io"

internal/termapp/tui_hotkeys.go

@@ -1,4 +1,4 @@
-package main
+package termapp
 
 import (
 	"strings"

internal/termapp/tui_model.go

@@ -1,4 +1,4 @@
-package main
+package termapp
 
 import (
 	"fmt"

internal/termapp/tui_panels.go

@@ -1,4 +1,4 @@
-package main
+package termapp
 
 import (
 	"fmt"

internal/termapp/tui_render.go

@@ -1,4 +1,4 @@
-package main
+package termapp
 
 import (
 	"strings"

internal/termapp/tui_test.go

@@ -1,4 +1,4 @@
-package main
+package termapp
 
 import (
 	"strings"