Add Phase 5 enhancements: security, i18n, analysis, backup, notifications

- Database v8 migration: tags, pinned, avg_startup_ms columns
- Security scanning with CVE matching and batch scan
- Bundled library extraction and vulnerability reports
- Desktop notification system for security alerts
- Backup/restore system for AppImage configurations
- i18n framework with gettext support
- Runtime analysis and Wayland compatibility detection
- AppStream metadata and Flatpak-style build support
- File watcher module for live directory monitoring
- Preferences panel with GSettings integration
- CLI interface for headless operation
- Detail view: tabbed layout with ViewSwitcher in title bar,
  health score, sandbox controls, changelog links
- Library view: sort dropdown, context menu enhancements
- Dashboard: system status, disk usage, launch history
- Security report page with scan and export
- Packaging: meson build, PKGBUILD, metainfo

meson.build

@@ -0,0 +1,68 @@
+project(
+  'driftwood',
+  'rust',
+  version: '0.1.0',
+  license: 'GPL-3.0-or-later',
+  meson_version: '>= 0.62.0',
+)
+
+i18n = import('i18n')
+gnome = import('gnome')
+
+app_id = 'app.driftwood.Driftwood'
+prefix = get_option('prefix')
+bindir = prefix / get_option('bindir')
+datadir = prefix / get_option('datadir')
+localedir = prefix / get_option('localedir')
+iconsdir = datadir / 'icons'
+
+# Install desktop file
+install_data(
+  'data' / app_id + '.desktop',
+  install_dir: datadir / 'applications',
+)
+
+# Install AppStream metainfo
+install_data(
+  'data' / app_id + '.metainfo.xml',
+  install_dir: datadir / 'metainfo',
+)
+
+# Compile and install GSettings schema
+install_data(
+  'data' / app_id + '.gschema.xml',
+  install_dir: datadir / 'glib-2.0' / 'schemas',
+)
+gnome.post_install(glib_compile_schemas: true)
+
+# Build the Rust binary via Cargo
+cargo = find_program('cargo')
+cargo_build_type = get_option('buildtype') == 'release' ? '--release' : ''
+
+custom_target(
+  'driftwood-binary',
+  output: 'driftwood',
+  command: [
+    cargo, 'build',
+    cargo_build_type,
+    '--manifest-path', meson.project_source_root() / 'Cargo.toml',
+    '--target-dir', meson.project_build_root() / 'cargo-target',
+  ],
+  env: {
+    'LOCALEDIR': localedir,
+    'GSETTINGS_SCHEMA_DIR': datadir / 'glib-2.0' / 'schemas',
+  },
+  build_by_default: true,
+  install: false,
+)
+
+# Install the binary (from the cargo output directory)
+cargo_profile = get_option('buildtype') == 'release' ? 'release' : 'debug'
+install_data(
+  meson.project_build_root() / 'cargo-target' / cargo_profile / 'driftwood',
+  install_dir: bindir,
+  install_mode: 'rwxr-xr-x',
+)
+
+# Translations
+subdir('po')