feat(frontend): add instance editor modal with tabbed interface

- Create InstanceEditorModal.svelte with 4 tabs:
  * Info: Instance name, notes, metadata (created date, last played)
  * Version: Mod loader switcher and version display
  * Files: File browser for mods/resourcepacks/shaderpacks/saves/screenshots
  * Settings: Memory override and JVM arguments customization
- Wire InstanceEditorModal to InstancesView with Edit button
- Add FileInfo type definition to types/index.ts
- Fix accessibility issues: proper button roles, keyboard events
- All TypeScript and Svelte compilation errors resolved
- Enable comprehensive per-instance configuration management

1 files changed, 8 insertions, 0 deletions

diff --git a/ui/src/types/index.ts b/ui/src/types/index.ts
index 6632d58..b4412b8 100644
--- a/ui/src/types/index.ts
+++ b/ui/src/types/index.ts
@@ -222,3 +222,11 @@ export interface MemoryOverride {
   min: number; // MB
   max: number; // MB
 }
+
+export interface FileInfo {
+  name: string;
+  path: string;
+  is_directory: boolean;
+  size: number;
+  modified: number;
+}