fix(FN-4112): remove mobile preset grid scroll cap

- Remove the inner preset grid max-height and overflow cap in the New Agent dialog mobile layout
- Add a dashboard CSS regression test that asserts the mobile media block keeps the preset grid fully visible
- Add a patch changeset for @runfusion/fusion covering the mobile blank-space fix

Fusion-Task-Id: FN-4112

.changeset/fn-4112-new-agent-mobile-blank-space.md

@@ -0,0 +1,5 @@
+---
+"@runfusion/fusion": patch
+---
+
+Fix blank space at the bottom of the New Agent dialog on mobile by removing the inner preset-grid scroll cap so the dialog body scrolls naturally.

packages/dashboard/app/components/NewAgentDialog.css

@@ -670,4 +670,9 @@
   .agent-dialog-interview-btn {
     width: 100%;
   }
+
+  .agent-presets-grid {
+    max-height: none;
+    overflow-y: visible;
+  }
 }

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

@@ -1,4 +1,5 @@
 import { describe, it, expect, vi, beforeEach } from "vitest";
+import { loadAllAppCss } from "../../test/cssFixture";
 import { useState } from "react";
 import { render, screen, fireEvent, waitFor, within, act } from "@testing-library/react";
 import userEvent from "@testing-library/user-event";
@@ -191,6 +192,28 @@ function getStepZeroField(label: string | RegExp) {
   return screen.getByLabelText(label);
 }
 
+function extractMobileMediaBlocks(content: string): string {
+  const blocks: string[] = [];
+  const regex = /@media\s*\(\s*max-width:\s*768px\s*\)\s*\{/g;
+  let match: RegExpExecArray | null;
+
+  while ((match = regex.exec(content)) !== null) {
+    const startIdx = match.index + match[0].length;
+    let braceCount = 1;
+    let endIdx = startIdx;
+    while (braceCount > 0 && endIdx < content.length) {
+      if (content[endIdx] === "{") braceCount++;
+      if (content[endIdx] === "}") braceCount--;
+      endIdx++;
+    }
+    if (braceCount === 0) {
+      blocks.push(content.slice(startIdx, endIdx - 1));
+    }
+  }
+
+  return blocks.join("\n");
+}
+
 describe("NewAgentDialog", () => {
   const mockOnClose = vi.fn();
   const mockOnCreated = vi.fn();
@@ -205,6 +228,14 @@ describe("NewAgentDialog", () => {
     mockFetchDiscoveredSkills.mockResolvedValue(MOCK_SKILLS_RESPONSE);
   });
 
+  describe("mobile layout", () => {
+    it("removes the preset grid scroll cap inside the mobile media block", () => {
+      const mobileCss = extractMobileMediaBlocks(loadAllAppCss());
+
+      expect(mobileCss).toMatch(/\.agent-presets-grid\s*\{[^}]*max-height:\s*none;[^}]*overflow-y:\s*visible;/);
+    });
+  });
+
   describe("modal visibility", () => {
     it("renders nothing when isOpen is false", () => {
       const { container } = render(