feat(opencode): Phase 6 - Tauri command extensions for OpenCode

- Add import_opencode_providers_from_live command to provider.rs
- Register new command in lib.rs invoke_handler
- Update commands/mcp.rs: include OpenCode in sync_other_side logic
- Add McpService::import_from_opencode to import_mcp_from_apps
- Implement MCP sync/remove for OpenCode in services/mcp.rs
  - sync_server_to_app_no_config now calls sync_single_server_to_opencode
  - remove_server_from_app now calls remove_server_from_opencode

src-tauri/src/lib.rs

@@ -875,6 +875,8 @@ pub fn run() {
             commands::upsert_universal_provider,
             commands::delete_universal_provider,
             commands::sync_universal_provider,
+            // OpenCode specific
+            commands::import_opencode_providers_from_live,
             // Global upstream proxy
             commands::get_global_proxy_url,
             commands::set_global_proxy_url,