feat: centralize version in internal/version package, fix updater for pre-release tags, show version in footer

internal/version/version.go

@@ -0,0 +1,14 @@
+// Keywarden - Centralized SSH Key Management and Deployment
+// Copyright (C) 2026 Patrick Asmus (scriptos)
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+package version
+
+// Version is the current application version.
+// This is the SINGLE SOURCE OF TRUTH for the version number.
+// Update this value for each release.
+//
+// It can still be overridden at build time via:
+//
+//	go build -ldflags "-X git.techniverse.net/scriptos/keywarden/internal/version.Version=v1.0.0"
+var Version = "v0.3.0-alpha"