feat: add theme registry distribution

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- Theme registry distribution: browse, install, uninstall, and update community themes from the plugin registry (Settings > Plugins > Browse, filtered by Themes category)
+
 ### Changed
 
 - Replaced fragmented Theme/DesignConstants/SQLEditorTheme/ToolbarDesignTokens with unified ThemeEngine

TablePro/Theme/RegistryThemeMeta.swift

@@ -0,0 +1,16 @@
+import Foundation
+
+internal struct RegistryThemeMeta: Codable {
+    var installed: [InstalledRegistryTheme]
+
+    init(installed: [InstalledRegistryTheme] = []) {
+        self.installed = installed
+    }
+}
+
+internal struct InstalledRegistryTheme: Codable, Identifiable {
+    let id: String
+    let registryPluginId: String
+    let version: String
+    let installedDate: Date
+}