feat(reader): 增强阅读器功能与 UI 测试支持

- 新增字体选择（系统/宋体/圆体/等宽）与暗色图片柔化配置
- 文本选择改为自定义手势+操作栏（拷贝/高亮/批注）
- 添加 accessibilityIdentifier 支持自动化 UI 测试
- 新增 UITests 覆盖阅读器打开/关闭、工具栏、设置面板、批注等
- 添加 Demo 测试用 EPUB 书源（宝山辽墓材料与释读）
- 新增文档：UI 自动化测试、功能开发计划、阅读器规划

ReadViewDemo/ReadViewDemoUITests/ReaderUITests/ReaderAnnotationTests.swift

@@ -0,0 +1,37 @@
+import XCTest
+
+final class ReaderAnnotationTests: XCTestCase {
+    private let app = XCUIApplication()
+
+    override func setUpWithError() throws {
+        continueAfterFailure = false
+    }
+
+    func testSelectionMenuCreatesHighlight() {
+        app.launchAndOpenSampleBook(pageNumber: 2)
+        app.waitForReader()
+
+        let content = app.textViews[IDs.readerSelectionText].firstMatch
+        XCTAssertTrue(content.waitForExistence(timeout: 5), "阅读内容区域未出现")
+
+        let start = content.coordinate(withNormalizedOffset: CGVector(dx: 0.35, dy: 0.42))
+        let end = content.coordinate(withNormalizedOffset: CGVector(dx: 0.68, dy: 0.42))
+        start.press(forDuration: 0.6, thenDragTo: end)
+
+        app.waitForReaderState(containing: "selection=1", timeout: 5)
+
+        let highlightMenuItem = app.menuItems["高亮"]
+        let highlightButton = app.buttons["高亮"]
+        let highlightActionButton = app.buttons[IDs.readerSelectionHighlight]
+        if highlightMenuItem.waitForExistence(timeout: 3) {
+            highlightMenuItem.tap()
+        } else if highlightActionButton.waitForExistence(timeout: 3) {
+            highlightActionButton.tap()
+        } else {
+            XCTAssertTrue(highlightButton.waitForExistence(timeout: 3), "选中文本后未出现高亮菜单")
+            highlightButton.tap()
+        }
+
+        app.waitForReaderState(containing: "highlights=1", timeout: 8)
+    }
+}