feat(navigator): add currentTabCode + currentFilter to UI store (P2 prep)

setTab(code) atomically updates currentTabCode and resets currentFilter
to '' — switching tabs starts a fresh search context. setFilter(value)
updates only the filter — the user is typing in the same tab.

TDD: 3 new cases (16 total in navigatorUiStore.test).

src/hooks/navigator/navigatorUiStore.test.ts

@@ -10,7 +10,9 @@ const INITIAL = {
     isOpenSavesSearches: false,
     isLoading: false,
     needsInit: true,
-    needsSearch: false
+    needsSearch: false,
+    currentTabCode: '',
+    currentFilter: ''
 };
 
 describe('useNavigatorUiStore', () =>
@@ -32,6 +34,8 @@ describe('useNavigatorUiStore', () =>
         expect(s.isLoading).toBe(false);
         expect(s.needsInit).toBe(true);
         expect(s.needsSearch).toBe(false);
+        expect(s.currentTabCode).toBe('');
+        expect(s.currentFilter).toBe('');
     });
 
     describe('show / hide / toggle', () =>
@@ -141,4 +145,31 @@ describe('useNavigatorUiStore', () =>
             expect(useNavigatorUiStore.getState().needsSearch).toBe(false);
         });
     });
+
+    describe('tab + filter', () =>
+    {
+        it("setTab('public') sets currentTabCode and clears currentFilter", () =>
+        {
+            useNavigatorUiStore.setState({ currentTabCode: 'events', currentFilter: 'habbo' });
+            useNavigatorUiStore.getState().setTab('public');
+            expect(useNavigatorUiStore.getState().currentTabCode).toBe('public');
+            expect(useNavigatorUiStore.getState().currentFilter).toBe('');
+        });
+
+        it("setFilter('cocco') sets currentFilter without touching tab", () =>
+        {
+            useNavigatorUiStore.getState().setTab('events');
+            useNavigatorUiStore.getState().setFilter('cocco');
+            expect(useNavigatorUiStore.getState().currentTabCode).toBe('events');
+            expect(useNavigatorUiStore.getState().currentFilter).toBe('cocco');
+        });
+
+        it('setTab on same code still resets currentFilter', () =>
+        {
+            useNavigatorUiStore.setState({ currentTabCode: 'public', currentFilter: 'test' });
+            useNavigatorUiStore.getState().setTab('public');
+            expect(useNavigatorUiStore.getState().currentTabCode).toBe('public');
+            expect(useNavigatorUiStore.getState().currentFilter).toBe('');
+        });
+    });
 });

src/hooks/navigator/navigatorUiStore.ts

@@ -10,6 +10,8 @@ export type NavigatorUiState = {
     isLoading: boolean;
     needsInit: boolean;
     needsSearch: boolean;
+    currentTabCode: string;
+    currentFilter: string;
 };
 
 export type NavigatorUiActions = {
@@ -28,6 +30,8 @@ export type NavigatorUiActions = {
     markInitDone(): void;
     requestSearch(): void;
     consumeSearchRequest(): void;
+    setTab(code: string): void;
+    setFilter(value: string): void;
 };
 
 export const useNavigatorUiStore = createNitroStore<NavigatorUiState & NavigatorUiActions>()((set) => ({
@@ -40,6 +44,8 @@ export const useNavigatorUiStore = createNitroStore<NavigatorUiState & Navigator
     isLoading: false,
     needsInit: true,
     needsSearch: false,
+    currentTabCode: '',
+    currentFilter: '',
 
     show: () => set({ isVisible: true, needsSearch: true }),
     hide: () => set({ isVisible: false }),
@@ -57,5 +63,7 @@ export const useNavigatorUiStore = createNitroStore<NavigatorUiState & Navigator
     markReady: () => set({ isReady: true }),
     markInitDone: () => set({ needsInit: false }),
     requestSearch: () => set({ needsSearch: true }),
-    consumeSearchRequest: () => set({ needsSearch: false })
+    consumeSearchRequest: () => set({ needsSearch: false }),
+    setTab: (code) => set({ currentTabCode: code, currentFilter: '' }),
+    setFilter: (value) => set({ currentFilter: value })
 }));