chore(ui): refactor workspace to monorepo (#70)

## Summary by Sourcery

Refactor the UI project structure into a pnpm monorepo packages layout
and align tooling and automation with the new paths.

Enhancements:
- Reorganize the UI app from the root ui directory into packages/ui
within a pnpm workspace.
- Update pnpm workspace configuration to include all packages under
packages/*.
- Adjust paths in changeset configuration so the @dropout/ui package
resolves from packages/ui.

Build:
- Update pre-commit configuration paths and arguments to reflect the new
UI location and normalize hook argument formatting.
- Update Dependabot configuration so npm updates target /packages/ui
instead of /ui.

CI:
- Update GitHub Actions workflows to watch packages/** instead of ui/**
and to run frontend tasks from packages/ui.
- Update pnpm cache dependency paths in workflows to use the root
pnpm-lock.yaml.
- Simplify frontend install steps in test workflows to run from the
repository root.

Chores:
- Add a new index.html under packages/ui and remove the old
ui/index.html to match the new project layout.

1 files changed, 106 insertions, 0 deletions

diff --git a/packages/ui/src/lib/modLoaderApi.ts b/packages/ui/src/lib/modLoaderApi.ts
new file mode 100644
index 0000000..75f404a
--- /dev/null
+++ b/packages/ui/src/lib/modLoaderApi.ts
@@ -0,0 +1,106 @@
+/**
+ * Mod Loader API service for Fabric and Forge integration.
+ * This module provides functions to interact with the Tauri backend
+ * for mod loader version management.
+ */
+
+import { invoke } from "@tauri-apps/api/core";
+import type {
+  FabricGameVersion,
+  FabricLoaderVersion,
+  FabricLoaderEntry,
+  InstalledFabricVersion,
+  ForgeVersion,
+  InstalledForgeVersion,
+} from "../types";
+
+// ==================== Fabric API ====================
+
+/**
+ * Get all Minecraft versions supported by Fabric.
+ */
+export async function getFabricGameVersions(): Promise<FabricGameVersion[]> {
+  return invoke<FabricGameVersion[]>("get_fabric_game_versions");
+}
+
+/**
+ * Get all available Fabric loader versions.
+ */
+export async function getFabricLoaderVersions(): Promise<FabricLoaderVersion[]> {
+  return invoke<FabricLoaderVersion[]>("get_fabric_loader_versions");
+}
+
+/**
+ * Get Fabric loaders available for a specific Minecraft version.
+ */
+export async function getFabricLoadersForVersion(
+  gameVersion: string,
+): Promise<FabricLoaderEntry[]> {
+  return invoke<FabricLoaderEntry[]>("get_fabric_loaders_for_version", {
+    gameVersion,
+  });
+}
+
+/**
+ * Install Fabric loader for a specific Minecraft version.
+ */
+export async function installFabric(
+  gameVersion: string,
+  loaderVersion: string,
+): Promise<InstalledFabricVersion> {
+  return invoke<InstalledFabricVersion>("install_fabric", {
+    gameVersion,
+    loaderVersion,
+  });
+}
+
+/**
+ * List all installed Fabric versions.
+ */
+export async function listInstalledFabricVersions(): Promise<string[]> {
+  return invoke<string[]>("list_installed_fabric_versions");
+}
+
+/**
+ * Check if Fabric is installed for a specific version combination.
+ */
+export async function isFabricInstalled(
+  gameVersion: string,
+  loaderVersion: string,
+): Promise<boolean> {
+  return invoke<boolean>("is_fabric_installed", {
+    gameVersion,
+    loaderVersion,
+  });
+}
+
+// ==================== Forge API ====================
+
+/**
+ * Get all Minecraft versions supported by Forge.
+ */
+export async function getForgeGameVersions(): Promise<string[]> {
+  return invoke<string[]>("get_forge_game_versions");
+}
+
+/**
+ * Get Forge versions available for a specific Minecraft version.
+ */
+export async function getForgeVersionsForGame(gameVersion: string): Promise<ForgeVersion[]> {
+  return invoke<ForgeVersion[]>("get_forge_versions_for_game", {
+    gameVersion,
+  });
+}
+
+/**
+ * Install Forge for a specific Minecraft version.
+ */
+export async function installForge(
+  gameVersion: string,
+  forgeVersion: string,
+): Promise<InstalledForgeVersion> {
+  return invoke<InstalledForgeVersion>("install_forge", {
+    gameVersion,
+    forgeVersion,
+  });
+}