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/main_build.go

@@ -0,0 +1,52 @@
+// 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 NewMainBuilder(
+	cfg Config,
+	mgr manager.Manager,
+	repos PackageFinder,
+	scriptExecutor ScriptExecutor,
+	installerExecutor InstallerExecutor,
+) (*Builder, error) {
+	builder := &Builder{
+		scriptExecutor: scriptExecutor,
+		cacheExecutor: &Cache{
+			cfg,
+		},
+		scriptResolver: &ScriptResolver{
+			cfg,
+		},
+		scriptViewerExecutor: &ScriptViewer{
+			config: cfg,
+		},
+		checkerExecutor: &Checker{
+			mgr,
+		},
+		installerExecutor: installerExecutor,
+		sourceExecutor: &SourceDownloader{
+			cfg,
+		},
+		repos: repos,
+	}
+
+	return builder, nil
+}