fix: subagent unique ID matching + AgentState serialization + pre-existing TS errors

- S-3: Thread task_id (UUID) through all 6 layers (LoopEvent → StreamChatEvent → kernel-types → gateway-client → streamStore) so subtasks are matched by ID, not description string
- AgentState: Add #[serde(rename_all = "lowercase")] to fix PascalCase serialization ("Running" → "running"), update frontend matcher
- S-1: Remove unused onClose prop from ArtifactPanel + ChatArea call site
- Fix hooks/index.ts: remove orphaned useAutomationEvents re-exports (module deleted)
- Fix types/index.ts: remove orphaned automation type/value re-exports (module deleted)
- Fix ChatArea.tsx: framer-motion 12 + React 19 type compat — use createElement + explicit any return type to avoid unknown-in-JSX-child error

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

desktop/src/store/chat/streamStore.ts

@@ -382,7 +382,7 @@ export const useStreamStore = create<StreamState>()(
               }
             }
           },
-          onSubtaskStatus: (description: string, status: string, detail?: string) => {
+          onSubtaskStatus: (taskId: string, description: string, status: string, detail?: string) => {
             // Map backend status to frontend Subtask status
             const statusMap: Record<string, Subtask['status']> = {
               started: 'pending',
@@ -396,12 +396,12 @@ export const useStreamStore = create<StreamState>()(
               msgs.map(m => {
                 if (m.id !== assistantId) return m;
                 const subtasks = [...(m.subtasks || [])];
-                const existingIdx = subtasks.findIndex(st => st.description === description);
+                const existingIdx = subtasks.findIndex(st => st.id === taskId);
                 if (existingIdx >= 0) {
                   subtasks[existingIdx] = { ...subtasks[existingIdx], status: mappedStatus, result: detail };
                 } else {
                   subtasks.push({
-                    id: `subtask_${Date.now()}_${generateRandomString(4)}`,
+                    id: taskId,
                     description,
                     status: mappedStatus,
                     result: detail,