refactor: move pkg/ to internal/ and update imports

Restructure project by relocating package contents from pkg/ to internal/ to better reflect internal-only usage. This commit is initial step to prepare project for public api

internal/build/installer.go

@@ -0,0 +1,54 @@
+// ALR - Any Linux Repository
+// Copyright (C) 2025 The ALR Authors
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package build
+
+import (
+	"gitea.plemya-x.ru/Plemya-x/ALR/internal/manager"
+)
+
+func NewInstaller(mgr manager.Manager) *Installer {
+	return &Installer{
+		mgr: mgr,
+	}
+}
+
+type Installer struct{ mgr manager.Manager }
+
+func (i *Installer) InstallLocal(paths []string, opts *manager.Opts) error {
+	return i.mgr.InstallLocal(opts, paths...)
+}
+
+func (i *Installer) Install(pkgs []string, opts *manager.Opts) error {
+	return i.mgr.Install(opts, pkgs...)
+}
+
+func (i *Installer) RemoveAlreadyInstalled(pkgs []string) ([]string, error) {
+	filteredPackages := []string{}
+
+	for _, dep := range pkgs {
+		installed, err := i.mgr.IsInstalled(dep)
+		if err != nil {
+			return nil, err
+		}
+		if installed {
+			continue
+		}
+		filteredPackages = append(filteredPackages, dep)
+	}
+
+	return filteredPackages, nil
+}