feat: import existing smb.conf and /etc/exports on first boot

Adds auto-detection of pre-existing Samba shares and NFS exports when
nasctl is installed on a host that already has these configs.

New package internal/importer parses smb.conf (INI-style) and
/etc/exports (line-based) and imports them into SQLite.

Imported shares/exports are marked dirty so the user must review
and apply manually before any file is overwritten.

Backup: before the first Apply, each module backs up the original
config to <path>.nasctl.bak.<timestamp> (one time only).

New CLI flag --import-on-boot / NASCTL_IMPORT_ON_BOOT env var
(default false, opt-in).

New API endpoints:
  GET  /api/import/status
  POST /api/import/samba
  POST /api/import/nfs

New DB methods ReplaceSambaShares/ReplaceNFSExports (transactional
replace-all), guarded by import.samba.done / import.nfs.done
settings flags.

internal/web/auth.go

@@ -174,11 +174,15 @@ type Server struct {
 	Engine       *engine.Engine
 	AllowedRoots []string
 	Auth         *AuthService
+	SMBConfPath  string
+	ExportsPath  string
 }
 
 type Options struct {
 	AllowedRoots []string
 	Auth         *AuthService
+	SMBConfPath  string
+	ExportsPath  string
 }
 
 func NewServer(database *db.DB, eng *engine.Engine, opts Options) *Server {
@@ -187,6 +191,8 @@ func NewServer(database *db.DB, eng *engine.Engine, opts Options) *Server {
 		Engine:       eng,
 		AllowedRoots: opts.AllowedRoots,
 		Auth:         opts.Auth,
+		SMBConfPath:  opts.SMBConfPath,
+		ExportsPath:  opts.ExportsPath,
 	}
 }
 

internal/web/handlers_import.go

@@ -0,0 +1,124 @@
+package web
+
+import (
+	"net/http"
+	"time"
+
+	"github.com/darroyo/nasctl/internal/db"
+	"github.com/darroyo/nasctl/internal/importer"
+	"github.com/darroyo/nasctl/internal/modules/nfs"
+	"github.com/darroyo/nasctl/internal/modules/samba"
+)
+
+type importStatus struct {
+	Samba   moduleImportStatus `json:"samba"`
+	NFS     moduleImportStatus `json:"nfs"`
+}
+
+type moduleImportStatus struct {
+	Done         bool   `json:"done"`
+	LastImportAt string `json:"last_import_at,omitempty"`
+	Count        int    `json:"count,omitempty"`
+}
+
+func (s *Server) handleImportStatus(w http.ResponseWriter, r *http.Request) {
+	sambaDone, _, _ := s.DB.GetSetting("import.samba.done")
+	nfsDone, _, _ := s.DB.GetSetting("import.nfs.done")
+
+	shares, _ := s.DB.ListSambaShares()
+	exports, _ := s.DB.ListNFSExports()
+
+	status := importStatus{
+		Samba: moduleImportStatus{
+			Done:  sambaDone == "true",
+			Count: len(shares),
+		},
+		NFS: moduleImportStatus{
+			Done:  nfsDone == "true",
+			Count: len(exports),
+		},
+	}
+
+	if ts, ok, _ := s.DB.GetSetting("import.samba.at"); ok {
+		status.Samba.LastImportAt = ts
+	}
+	if ts, ok, _ := s.DB.GetSetting("import.nfs.at"); ok {
+		status.NFS.LastImportAt = ts
+	}
+
+	writeJSON(w, http.StatusOK, status)
+}
+
+func (s *Server) handleImportSamba(w http.ResponseWriter, r *http.Request) {
+	if err := importer.ResetImportFlags(r.Context(), s.DB); err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+
+	shares, err := importer.ImportSambaShares(s.SMBConfPath)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+
+	if len(shares) == 0 {
+		writeJSON(w, http.StatusOK, map[string]any{"imported": 0, "message": "no shares found in smb.conf"})
+		return
+	}
+
+	if err := s.DB.ReplaceSambaShares(shares); err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+
+	if err := s.DB.MarkDirty(samba.ModuleName); err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+
+	_ = s.DB.SetSetting("import.samba.done", "true")
+	_ = s.DB.SetSetting("import.samba.at", time.Now().Format(time.RFC3339))
+
+	writeJSON(w, http.StatusOK, map[string]any{"imported": len(shares)})
+}
+
+func (s *Server) handleImportNFS(w http.ResponseWriter, r *http.Request) {
+	if err := importer.ResetImportFlags(r.Context(), s.DB); err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+
+	exports, err := importer.ImportNFSExports(s.ExportsPath)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+
+	if len(exports) == 0 {
+		writeJSON(w, http.StatusOK, map[string]any{"imported": 0, "message": "no exports found in exports file"})
+		return
+	}
+
+	if err := s.DB.ReplaceNFSExports(exports); err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+
+	if err := s.DB.MarkDirty(nfs.ModuleName); err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+
+	_ = s.DB.SetSetting("import.nfs.done", "true")
+	_ = s.DB.SetSetting("import.nfs.at", time.Now().Format(time.RFC3339))
+
+	writeJSON(w, http.StatusOK, map[string]any{"imported": len(exports)})
+}
+
+type dbExporter interface {
+	ReplaceSambaShares(shares []db.SambaShare) error
+	ReplaceNFSExports(exports []db.NFSExport) error
+	MarkDirty(module string) error
+}
+
+var _ dbExporter = (*db.DB)(nil)

internal/web/router.go

@@ -30,6 +30,10 @@ func NewRouter(s *Server) chi.Router {
 			protected.Get("/apply/log", s.handleApplyLog)
 			protected.Get("/system/status", s.handleSystemStatus)
 
+			protected.Get("/import/status", s.handleImportStatus)
+			protected.Post("/import/samba", s.handleImportSamba)
+			protected.Post("/import/nfs", s.handleImportNFS)
+
 			protected.Route("/samba/shares", func(shares chi.Router) {
 				shares.Get("/", s.handleListSambaShares)
 				shares.Post("/", s.handleCreateSambaShare)