FN-6766: fix mobile nav icon spacing

Keeps mobile bottom navigation icons evenly centered across tab variants.

- Make each mobile nav tab an equal-width flex column that ignores intrinsic label width.
- Center and truncate labels without affecting icon spacing.
- Add coverage for optional tabs, active tabs, badges, status dots, and overflow plugin views.
- Add a patch changeset for the published CLI bundle.

Files changed:
 .changeset/fn-6766-mobile-nav-spacing.md           |  5 ++
 packages/dashboard/app/components/MobileNavBar.css | 18 ++--
 .../app/components/__tests__/MobileNavBar.test.tsx | 95 ++++++++++++++++++++++
 3 files changed, 113 insertions(+), 5 deletions(-)

Fusion-Task-Id: FN-6766

Fusion-Task-Lineage: 0fe92813-9110-4bc9-b0d0-39d98dc7dba9

.changeset/fn-6766-mobile-nav-spacing.md

@@ -0,0 +1,5 @@
+---
+"@runfusion/fusion": patch
+---
+
+Fix mobile bottom tab navigation icon spacing so every tab uses an equal-width column across optional tabs, badges, and status dots.

packages/dashboard/app/components/MobileNavBar.css

@@ -74,23 +74,28 @@
 }
 
 /* Individual tab button */
+/*
+FNXC:MobileNav 2026-06-20-02:04:
+Every mobile nav tab must be an equal-width column with a centered icon so inter-icon spacing stays uniform across tab counts, long labels, active state, badges, and status dots.
+Use a zero flex basis plus min-width:0 so intrinsic label width cannot bias flex distribution; badges and status dots stay absolutely positioned and out of flow.
+*/
 .mobile-nav-tab {
-  flex: 1;
+  flex: 1 1 0;
+  min-width: 0;
   display: flex;
   flex-direction: column;
   align-items: center;
   justify-content: center;
-  gap: 2px;
-  min-width: 36px;
+  gap: calc(var(--space-xs) / 2);
   min-height: 36px;
-  padding: 6px 0;
+  padding: calc(var(--space-sm) - (var(--space-xs) / 2)) 0;
   background: none;
   border: none;
   color: var(--text-muted);
   font-size: 10px;
   line-height: 1.2;
   cursor: pointer;
-  transition: color 0.15s ease;
+  transition: color var(--transition-fast);
   position: relative;
   -webkit-tap-highlight-color: transparent;
 }
@@ -120,11 +125,14 @@
 }
 
 .mobile-nav-tab-label {
+  width: 100%;
+  min-width: 0;
   max-width: 100%;
   overflow: hidden;
   text-overflow: ellipsis;
   font-size: 10px;
   line-height: 1.2;
+  text-align: center;
   white-space: nowrap;
 }
 

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

@@ -1,3 +1,5 @@
+import { readFileSync } from "fs";
+import { resolve } from "path";
 import { beforeEach, describe, expect, it, vi } from "vitest";
 import { fireEvent, render, screen, waitFor } from "@testing-library/react";
 import { MobileNavBar } from "../MobileNavBar";
@@ -26,6 +28,48 @@ function mockViewport(mode: "mobile" | "desktop") {
   });
 }
 
+const mobileNavCss = readFileSync(resolve(process.cwd(), "app/components/MobileNavBar.css"), "utf8");
+
+function extractRuleBlock(css: string, selector: string): string {
+  const escapedSelector = selector.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
+  const match = css.match(new RegExp(`${escapedSelector}\\s*\\{([\\s\\S]*?)\\}`));
+  return match?.[1] ?? "";
+}
+
+function getRenderedMobileTabs(container: HTMLElement): HTMLElement[] {
+  return Array.from(container.querySelectorAll<HTMLElement>(".mobile-nav-bar > .mobile-nav-tab"));
+}
+
+function expectUniformMobileNavColumns(container: HTMLElement, expectedTabCount: number) {
+  const tabs = getRenderedMobileTabs(container);
+  expect(tabs).toHaveLength(expectedTabCount);
+
+  const tabRule = extractRuleBlock(mobileNavCss, ".mobile-nav-tab");
+  expect(tabRule).toContain("flex: 1 1 0");
+  expect(tabRule).toContain("min-width: 0");
+  expect(tabRule).toContain("align-items: center");
+  expect(tabRule).toMatch(/padding:\s*[^;]+\s+0;/);
+  expect(tabRule).not.toMatch(/margin-left|margin-right/);
+
+  const labelRule = extractRuleBlock(mobileNavCss, ".mobile-nav-tab-label");
+  expect(labelRule).toContain("width: 100%");
+  expect(labelRule).toContain("min-width: 0");
+  expect(labelRule).toContain("text-align: center");
+
+  for (const tab of tabs) {
+    expect(tab.className).toContain("mobile-nav-tab");
+    expect(tab.querySelector(".mobile-nav-tab-label")).toBeInTheDocument();
+  }
+
+  if (container.querySelector(".mobile-nav-tab-badge")) {
+    expect(extractRuleBlock(mobileNavCss, ".mobile-nav-tab-badge")).toContain("position: absolute");
+  }
+
+  if (container.querySelector(".mobile-nav-chat-unread-dot")) {
+    expect(extractRuleBlock(mobileNavCss, ".mobile-nav-chat-unread-dot")).toContain("position: absolute");
+  }
+}
+
 const createDefaultProps = () => ({
   view: "board" as const,
   onChangeView: vi.fn(),
@@ -105,6 +149,57 @@ describe("MobileNavBar", () => {
     expect(screen.queryByTestId("mobile-nav-tab-skills")).toBeNull();
   });
 
+  it("keeps every mobile tab in an equal-width column across tab, active, badge, and status-dot variants", () => {
+    const sevenTabRender = render(
+      <MobileNavBar
+        {...createDefaultProps()}
+        showSkillsTab={false}
+        view="command-center"
+        chatHasUnreadResponse={true}
+        mailboxUnreadCount={7}
+        mailboxPendingApprovalCount={2}
+      />,
+    );
+    expectUniformMobileNavColumns(sevenTabRender.container, 7);
+    expect(screen.getByTestId("mobile-nav-tab-command-center").className).toContain("mobile-nav-tab--active");
+    expect(screen.getByLabelText("Unread chat response")).toBeInTheDocument();
+    expect(screen.getByLabelText("Pending approvals")).toBeInTheDocument();
+    expect(screen.getByTestId("mobile-nav-tab-mailbox").querySelector(".mobile-nav-tab-badge")?.textContent).toBe("7");
+    sevenTabRender.unmount();
+
+    const eightTabRender = render(
+      <MobileNavBar
+        {...createDefaultProps()}
+        showSkillsTab={true}
+        view="skills"
+        chatHasUnreadResponse={true}
+        mailboxUnreadCount={101}
+        mailboxPendingApprovalCount={1}
+      />,
+    );
+    expectUniformMobileNavColumns(eightTabRender.container, 8);
+    expect(screen.getByTestId("mobile-nav-tab-skills").className).toContain("mobile-nav-tab--active");
+    expect(screen.getByTestId("mobile-nav-tab-mailbox").querySelector(".mobile-nav-tab-badge")?.textContent).toBe("99+");
+    eightTabRender.unmount();
+
+    const pluginVariantRender = render(
+      <MobileNavBar
+        {...createDefaultProps()}
+        showSkillsTab={true}
+        pluginDashboardViews={[
+          {
+            pluginId: "fusion-plugin-spacing-check",
+            view: { viewId: "wide", label: "Very Long Plugin Destination", componentPath: "./WidePluginView", icon: "Workflow", placement: "primary", order: 1 },
+          },
+        ]}
+      />,
+    );
+    expectUniformMobileNavColumns(pluginVariantRender.container, 8);
+    expect(screen.queryByTestId("mobile-nav-tab-plugin-fusion-plugin-spacing-check-wide")).toBeNull();
+    fireEvent.click(screen.getByTestId("mobile-nav-tab-more"));
+    expect(screen.getByTestId("mobile-more-item-plugin-fusion-plugin-spacing-check-wide")).toBeDefined();
+  });
+
   it("keeps Todos in the mobile More sheet when todoView is enabled", () => {
     const onOpenTodos = vi.fn();
     render(