fix(stores): whitelist durable fields in persist partialize

chat/terminal/panel persist configs leaked actions and transient state
into localStorage. Replace the chat full-state spread with an explicit
durable whitelist, and add partialize to terminal and panel (which had
none) so isResizing and _hasHydrated are no longer persisted. Panel keeps
activeTab + panelWidth because the layout.tsx blocking script reads them
from panel-state to set data-panel-active-tab before hydration (SSR
tab-flash prevention).

Harden sim-stores doctrine: persist MUST use an explicit partialize
whitelist; never persist transient flags or _hasHydrated.

Author: waleedlatif1

.claude/rules/sim-stores.md

@@ -57,7 +57,7 @@ export const useFeatureStore = create<FeatureState>()(
 
 1. Use `devtools` middleware (named stores)
 2. Use `persist` only when data should survive reload
-3. `partialize` to persist only necessary state
+3. `persist` MUST use `partialize` with an explicit whitelist of the durable fields. NEVER persist transient flags (`isResizing`, drag/hover state) or `_hasHydrated`, and never spread the whole state (`{ ...state }`) — it leaks actions and transient state into storage
 4. `_hasHydrated` pattern for persisted stores needing hydration tracking
 5. Immutable updates only
 6. `set((state) => ...)` when depending on previous state

apps/sim/stores/chat/store.ts

@@ -254,8 +254,20 @@ export const useChatStore = create<ChatState>()(
       }),
       {
         name: 'chat-store',
+        /**
+         * Persist only the durable chat state — message history (with transient
+         * blob `previewUrl`s stripped since they are not valid across reloads),
+         * per-workflow output selections and conversation ids, and the floating
+         * chat's open state, position, and dimensions. Actions and any transient
+         * UI flags are intentionally excluded.
+         */
         partialize: (state) => ({
-          ...state,
+          isChatOpen: state.isChatOpen,
+          chatPosition: state.chatPosition,
+          chatWidth: state.chatWidth,
+          chatHeight: state.chatHeight,
+          selectedWorkflowOutputs: state.selectedWorkflowOutputs,
+          conversationIds: state.conversationIds,
           messages: state.messages.map((msg) => ({
             ...msg,
             attachments: msg.attachments?.map((att) => ({

apps/sim/stores/panel/store.ts

@@ -40,6 +40,17 @@ export const usePanelStore = create<PanelState>()(
     }),
     {
       name: 'panel-state',
+      /**
+       * Persist only the durable panel preferences. `activeTab` MUST be kept:
+       * the blocking script in `app/layout.tsx` reads it from this persisted
+       * `panel-state` entry to set `data-panel-active-tab` before hydration,
+       * preventing a tab flash. The transient `isResizing` drag flag and the
+       * `_hasHydrated` hydration marker are excluded.
+       */
+      partialize: (state) => ({
+        panelWidth: state.panelWidth,
+        activeTab: state.activeTab,
+      }),
       onRehydrateStorage: () => (state) => {
         // Sync CSS variables with stored state after rehydration
         if (state && typeof window !== 'undefined') {

apps/sim/stores/terminal/store.ts

@@ -93,6 +93,19 @@ export const useTerminalStore = create<TerminalState>()(
     }),
     {
       name: 'terminal-state',
+      /**
+       * Persist only the durable terminal UI preferences. The transient
+       * `isResizing` drag flag and the `_hasHydrated` hydration marker are
+       * excluded so they always start fresh on load.
+       */
+      partialize: (state) => ({
+        terminalHeight: state.terminalHeight,
+        lastExpandedHeight: state.lastExpandedHeight,
+        outputPanelWidth: state.outputPanelWidth,
+        openOnRun: state.openOnRun,
+        wrapText: state.wrapText,
+        structuredView: state.structuredView,
+      }),
       /**
        * Synchronizes the `--terminal-height` CSS custom property with the
        * persisted store value after client-side rehydration.