feat: update README assets, refine feature views and design tokens

Replace incorrect README icon with actual Atlas app icon, add new
screenshots (about, settings, privilege), improve feature view
responsiveness and empty states, adjust design system brand tokens
and localization strings, add icon generation script.

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

Packages/AtlasDomain/Tests/AtlasDomainTests/AtlasDomainTests.swift

@@ -9,7 +9,9 @@ final class AtlasDomainTests: XCTestCase {
 
     func testPrimaryRoutesMatchFrozenMVP() {
         XCTAssertEqual(
-            AtlasRoute.allCases.map(\.title),
+            AtlasRoute.allCases
+                .filter { $0 != .about }
+                .map(\.title),
             ["概览", "智能清理", "应用", "历史", "权限", "设置"]
         )
     }