feat: persist session state (folder, cursor, active pane) on exit and restore on launch

internal/config/session.go

@@ -0,0 +1,83 @@
+package config
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+
+	toml "github.com/pelletier/go-toml/v2"
+)
+
+// SessionState stores the UI state that should be restored on next launch.
+type SessionState struct {
+	ActivePane string         `toml:"active_pane"`
+	Left       PaneSession    `toml:"left"`
+	Right      PaneSession    `toml:"right"`
+}
+
+// PaneSession stores per-pane session state (path and selected entry name).
+type PaneSession struct {
+	Path      string `toml:"path"`
+	EntryName string `toml:"entry_name"`
+}
+
+// DefaultSessionPath returns the path to the session file.
+func DefaultSessionPath() (string, error) {
+	homeDir, err := os.UserHomeDir()
+	if err != nil {
+		return "", fmt.Errorf("resolve home dir: %w", err)
+	}
+	xdgDir := os.Getenv("XDG_CONFIG_HOME")
+	if xdgDir == "" {
+		xdgDir = filepath.Join(homeDir, ".config")
+	}
+	return filepath.Join(xdgDir, "vcom", "session.toml"), nil
+}
+
+// LoadSession reads the session state from disk.
+// Returns (SessionState, nil) on success, (empty, error) if file doesn't exist.
+func LoadSession() (SessionState, error) {
+	path, err := DefaultSessionPath()
+	if err != nil {
+		return SessionState{}, err
+	}
+
+	data, err := os.ReadFile(path)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return SessionState{}, nil
+		}
+		return SessionState{}, fmt.Errorf("read %s: %w", path, err)
+	}
+
+	var s SessionState
+	if err := toml.Unmarshal(data, &s); err != nil {
+		return SessionState{}, fmt.Errorf("parse %s: %w", path, err)
+	}
+	return s, nil
+}
+
+// SaveSession writes the session state to disk.
+func SaveSession(s SessionState) error {
+	path, err := DefaultSessionPath()
+	if err != nil {
+		return err
+	}
+
+	absPath, err := filepath.Abs(path)
+	if err != nil {
+		return fmt.Errorf("resolve %s: %w", path, err)
+	}
+	if err := os.MkdirAll(filepath.Dir(absPath), 0o755); err != nil {
+		return fmt.Errorf("mkdir %s: %w", filepath.Dir(absPath), err)
+	}
+
+	data, err := toml.Marshal(s)
+	if err != nil {
+		return fmt.Errorf("marshal session: %w", err)
+	}
+	if err := os.WriteFile(absPath, data, 0o644); err != nil {
+		return fmt.Errorf("write %s: %w", path, err)
+	}
+	return nil
+}

internal/ui/model.go

@@ -318,10 +318,15 @@ func NewModel(cfg config.Config, configPath string) (Model, error) {
 		model.ssh = sshSt
 	}
 
-	if err := model.reloadPane(PaneLeft, ""); err != nil {
+	// Apply saved session (overrides startup paths if a previous session exists)
+	applySession(&model)
+
+	leftPreserve := model.left.LoadCursor(model.left.Path)
+	rightPreserve := model.right.LoadCursor(model.right.Path)
+	if err := model.reloadPane(PaneLeft, leftPreserve); err != nil {
 		return Model{}, err
 	}
-	if err := model.reloadPane(PaneRight, ""); err != nil {
+	if err := model.reloadPane(PaneRight, rightPreserve); err != nil {
 		return Model{}, err
 	}
 	return model, nil
@@ -1136,6 +1141,7 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 		switch {
 		case key.Matches(msg, m.keys.Quit):
 			log.Printf("[KEY] Quit — exiting application")
+			m.saveSession()
 			m.cleanupArchiveMounts()
 			m.cleanupImageOverlay()
 			return m, tea.Quit
@@ -5244,6 +5250,66 @@ func selectedName(pane *BrowserPane) string {
 	return selected.Name
 }
 
+func (m *Model) saveSession() {
+	s := config.SessionState{
+		ActivePane: string(m.active),
+		Left: config.PaneSession{
+			Path:      m.left.Path,
+			EntryName: selectedName(&m.left),
+		},
+		Right: config.PaneSession{
+			Path:      m.right.Path,
+			EntryName: selectedName(&m.right),
+		},
+	}
+	if err := config.SaveSession(s); err != nil {
+		log.Printf("[SESSION] save failed: %v", err)
+	} else {
+		log.Printf("[SESSION] saved: active=%s left=%s right=%s", m.active, m.left.Path, m.right.Path)
+	}
+}
+
+func applySession(m *Model) {
+	s, err := config.LoadSession()
+	if err != nil {
+		log.Printf("[SESSION] load failed: %v", err)
+		return
+	}
+	if s.ActivePane == "" && s.Left.Path == "" && s.Right.Path == "" {
+		log.Printf("[SESSION] no previous session found")
+		return
+	}
+	log.Printf("[SESSION] loaded: active=%s left=%s right=%s", s.ActivePane, s.Left.Path, s.Right.Path)
+
+	applyPaneSession(&m.left, s.Left)
+	applyPaneSession(&m.right, s.Right)
+
+	if s.ActivePane == string(PaneRight) {
+		m.active = PaneRight
+	}
+}
+
+func applyPaneSession(pane *BrowserPane, ps config.PaneSession) {
+	if ps.Path == "" {
+		return
+	}
+	abs, err := filepath.Abs(ps.Path)
+	if err != nil {
+		log.Printf("[SESSION] skip pane path=%s: %v", ps.Path, err)
+		return
+	}
+	info, err := os.Stat(abs)
+	if err != nil || !info.IsDir() {
+		log.Printf("[SESSION] skip pane path=%s: not a directory or missing", abs)
+		return
+	}
+	pane.Path = abs
+	// Store entry name for cursor restore in reloadPane
+	if ps.EntryName != "" {
+		pane.cursorMemory = map[string]string{abs: ps.EntryName}
+	}
+}
+
 func metaSize(meta vfs.Metadata) string {
 	if !meta.SizeKnown {
 		return "press Space"