fix(FN-949): prevent bounce-back on Projects nav and show in mobile overflow

clearCurrentProject was triggering auto-reselect in useCurrentProject,
making the Projects button ineffective for single-project users. Added
explicit-clear flag to suppress auto-select. Also changed mobile overflow
menu to show Projects for single-project users (was gated to 2+ projects).

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

packages/dashboard/app/__tests__/tablet-header-controls.test.tsx

@@ -364,7 +364,7 @@ describe("tablet header controls", () => {
     fireEvent.click(screen.getByTitle("More header actions"));
     const btn = screen.getByTestId("overflow-project-selector-btn");
     expect(btn).toBeDefined();
-    expect(btn.textContent).toContain("Project One");
+    expect(btn.textContent).toContain("Projects");
   });
 
   // ── Desktop still shows everything inline ──────────────────────

packages/dashboard/app/components/Header.tsx

@@ -1,5 +1,5 @@
 import { useState, useEffect, useRef, useCallback, useMemo } from "react";
-import { Settings, Pause, Play, Square, LayoutGrid, List, Terminal, Lightbulb, Search, X, Activity, MoreHorizontal, Clock, Folder, History, GitBranch, Workflow, Bot, ChevronLeft, Target, Building2, ChevronRight, FileCode, Loader2, Grid3X3 } from "lucide-react";
+import { Settings, Pause, Play, Square, LayoutGrid, List, Terminal, Lightbulb, Search, X, Activity, MoreHorizontal, Clock, Folder, History, GitBranch, Workflow, Bot, ChevronLeft, Target, ChevronRight, FileCode, Loader2, Grid3X3 } from "lucide-react";
 import type { ProjectInfo } from "../api";
 import { fetchScripts } from "../api";
 import { ProjectSelector } from "./ProjectSelector";
@@ -573,16 +573,16 @@ export function Header({
             role="menu"
             aria-label="Additional header actions"
           >
-            {/* Switch Project - in overflow on mobile */}
-            {projects.length > 1 && onViewAllProjects && (
+            {/* Projects - in overflow on mobile */}
+            {projects.length >= 1 && onViewAllProjects && (
               <button
                 className="mobile-overflow-item"
                 onClick={() => handleOverflowAction(onViewAllProjects)}
                 role="menuitem"
                 data-testid="overflow-project-selector-btn"
               >
-                <Building2 size={16} />
-                <span>{currentProject ? currentProject.name : "Switch Project"}</span>
+                <Grid3X3 size={16} />
+                <span>Projects</span>
               </button>
             )}
             {/* Files - in overflow on mobile */}

packages/dashboard/app/components/__tests__/Header.test.tsx

@@ -625,8 +625,7 @@ describe("Header", () => {
       fireEvent.click(screen.getByTitle("More header actions"));
       const btn = screen.getByTestId("overflow-project-selector-btn");
       expect(btn).toBeDefined();
-      // Should show the current project name
-      expect(btn.textContent).toContain("Project One");
+      expect(btn.textContent).toContain("Projects");
     });
 
     it("overflow project selector calls onViewAllProjects when clicked", () => {
@@ -679,7 +678,7 @@ describe("Header", () => {
       expect(projectSvg!.innerHTML).not.toBe(filesSvg!.innerHTML);
     });
 
-    it("does not show switch project in overflow menu with single project", () => {
+    it("shows projects in overflow menu with single project", () => {
       const projects = [
         { id: "proj_1", name: "Project One", path: "/path/1", status: "active" as const, isolationMode: "in-process" as const, createdAt: "", updatedAt: "" },
       ];
@@ -692,7 +691,7 @@ describe("Header", () => {
         />
       );
       fireEvent.click(screen.getByTitle("More header actions"));
-      expect(screen.queryByTestId("overflow-project-selector-btn")).toBeNull();
+      expect(screen.queryByTestId("overflow-project-selector-btn")).not.toBeNull();
     });
 
     it("missions overflow menu item calls onOpenMissions when clicked", () => {

packages/dashboard/app/hooks/useCurrentProject.test.ts

@@ -143,13 +143,13 @@ describe("useCurrentProject", () => {
       result.current.clearCurrentProject();
     });
 
-    // With available projects, it re-defaults to first active and saves to localStorage
+    // After explicit clear, should stay null (no auto-select) so user can view overview
     await waitFor(() => {
-      expect(result.current.currentProject?.id).toBe("proj_1");
+      expect(result.current.currentProject).toBeNull();
     });
-    
-    // After re-defaulting, localStorage should have the default project
-    expect(localStorage.getItem("kb-dashboard-current-project")).toContain("proj_1");
+
+    // localStorage should be cleared
+    expect(localStorage.getItem("kb-dashboard-current-project")).toBeNull();
   });
 
   it("handles localStorage errors gracefully", async () => {

packages/dashboard/app/hooks/useCurrentProject.ts

@@ -1,4 +1,4 @@
-import { useState, useEffect, useCallback } from "react";
+import { useState, useEffect, useCallback, useRef } from "react";
 import type { ProjectInfo } from "../api";
 
 const STORAGE_KEY = "kb-dashboard-current-project";
@@ -8,7 +8,7 @@ export interface UseCurrentProjectResult {
   currentProject: ProjectInfo | null;
   /** Set the current project */
   setCurrentProject: (project: ProjectInfo | null) => void;
-  /** Clear the current project selection */
+  /** Clear the current project selection (suppresses auto-select) */
   clearCurrentProject: () => void;
   /** Whether we're still loading from localStorage */
   loading: boolean;
@@ -21,6 +21,9 @@ export interface UseCurrentProjectResult {
 export function useCurrentProject(availableProjects: ProjectInfo[]): UseCurrentProjectResult {
   const [currentProject, setCurrentProjectState] = useState<ProjectInfo | null>(null);
   const [loading, setLoading] = useState(true);
+  // When true, the user explicitly cleared the project (e.g. clicked "Projects")
+  // and we should not auto-select until they pick one manually.
+  const explicitlyClearedRef = useRef(false);
 
   // Load from localStorage on mount
   useEffect(() => {
@@ -50,15 +53,16 @@ export function useCurrentProject(availableProjects: ProjectInfo[]): UseCurrentP
         setCurrentProjectState(firstActive || availableProjects[0] || null);
         return;
       }
-      
+
       // Persist to localStorage
       try {
         localStorage.setItem(STORAGE_KEY, JSON.stringify(currentProject));
       } catch {
         // Ignore localStorage errors
       }
-    } else if (availableProjects.length > 0) {
+    } else if (availableProjects.length > 0 && !explicitlyClearedRef.current) {
       // No selection but projects available - default to first active
+      // Skip if user explicitly cleared (navigated to overview)
       const firstActive = availableProjects.find((p) => p.status === "active");
       if (firstActive) {
         setCurrentProjectState(firstActive);
@@ -67,6 +71,7 @@ export function useCurrentProject(availableProjects: ProjectInfo[]): UseCurrentP
   }, [currentProject, availableProjects, loading]);
 
   const setCurrentProject = useCallback((project: ProjectInfo | null) => {
+    explicitlyClearedRef.current = false;
     setCurrentProjectState(project);
     if (project) {
       try {
@@ -84,6 +89,7 @@ export function useCurrentProject(availableProjects: ProjectInfo[]): UseCurrentP
   }, []);
 
   const clearCurrentProject = useCallback(() => {
+    explicitlyClearedRef.current = true;
     setCurrentProjectState(null);
     try {
       localStorage.removeItem(STORAGE_KEY);