feat(grokbuild): add first-class Grok Build support (#5453)

* feat(grokbuild): add backend integration

* feat(grokbuild): add provider and management UI

* test(grokbuild): cover configuration and integrations

* fix(grokbuild): address backend review feedback

* fix(grokbuild): complete UI review feedback

* feat(grokbuild): add CLI lifecycle management

* fix(grokbuild): align provider icon fallback

* test(grokbuild): cover provider icon persistence

src-tauri/tests/import_export_sync.rs

@@ -748,6 +748,7 @@ command = "echo"
                 claude: false,
                 codex: false, // 初始未启用
                 gemini: false,
+                grokbuild: false,
                 opencode: false,
                 hermes: false,
             },
@@ -877,6 +878,7 @@ fn import_from_claude_merges_into_config() {
                 claude: false, // 初始未启用
                 codex: false,
                 gemini: false,
+                grokbuild: false,
                 opencode: false,
                 hermes: false,
             },