Add game lifecycle management and instance import/export tools (#117)

## Summary by Sourcery

Add centralized game process and instance lifecycle management, shared
cache-aware path resolution, and instance import/export/repair
capabilities across backend and UI.

New Features:
- Track a single running game process in the backend, expose stop-game
control, and emit structured game-exited events with instance and
version context.
- Introduce instance path resolution that supports shared caches for
versions, libraries, and assets, and use it across game start, install,
and version management APIs.
- Add import, export, and repair operations for instances, including
zip-based archive support and automatic recovery of on-disk instances.
- Expose new instance lifecycle and repair APIs to the frontend and wire
them through the client and instance store.
- Add per-instance start/stop controls in the instances view and
instance selection in the bottom bar for launching games.

Enhancements:
- Guard instance operations with per-instance locks and track active
operations such as launch, install, delete, and import/export.
- Improve handling of Microsoft login errors and polling status, with
clearer user feedback and safer interval management.
- Simplify config mutation during shared cache migration and centralize
instance directory resolution in the backend.
- Initialize a game lifecycle listener at app startup to keep UI state
in sync with backend game exit events.

Build:
- Configure the Vite dev server to use a fixed localhost host and port
for the UI dev environment.

1 files changed, 29 insertions, 0 deletions

diff --git a/packages/ui/src/client.ts b/packages/ui/src/client.ts
index 18d2377..6f354d2 100644
--- a/packages/ui/src/client.ts
+++ b/packages/ui/src/client.ts
@@ -12,6 +12,7 @@ import type {
   InstalledForgeVersion,
   InstalledVersion,
   Instance,
+  InstanceRepairResult,
   JavaCatalog,
   JavaDownloadInfo,
   JavaInstallation,
@@ -119,6 +120,16 @@ export function duplicateInstance(
   });
 }
 
+export function exportInstance(
+  instanceId: string,
+  archivePath: string,
+): Promise<string> {
+  return invoke<string>("export_instance", {
+    instanceId,
+    archivePath,
+  });
+}
+
 export function fetchAdoptiumJava(
   majorVersion: number,
   imageType: string,
@@ -267,6 +278,16 @@ export function installVersion(
   });
 }
 
+export function importInstance(
+  archivePath: string,
+  newName?: string,
+): Promise<Instance> {
+  return invoke<Instance>("import_instance", {
+    archivePath,
+    newName,
+  });
+}
+
 export function isFabricInstalled(
   instanceId: string,
   gameVersion: string,
@@ -351,6 +372,10 @@ export function refreshJavaCatalog(): Promise<JavaCatalog> {
   return invoke<JavaCatalog>("refresh_java_catalog");
 }
 
+export function repairInstances(): Promise<InstanceRepairResult> {
+  return invoke<InstanceRepairResult>("repair_instances");
+}
+
 export function resumeJavaDownloads(): Promise<JavaInstallation[]> {
   return invoke<JavaInstallation[]>("resume_java_downloads");
 }
@@ -383,6 +408,10 @@ export function startGame(
   });
 }
 
+export function stopGame(): Promise<string> {
+  return invoke<string>("stop_game");
+}
+
 export function startMicrosoftLogin(): Promise<DeviceCodeResponse> {
   return invoke<DeviceCodeResponse>("start_microsoft_login");
 }