feat: complete large-book pagination runtime and UI coverage

ReadViewDemo/ReadViewDemoUITests/Helpers/DemoReaderState.swift

@@ -0,0 +1,71 @@
+import XCTest
+
+struct DemoReaderState {
+    let rawValue: String
+    let fields: [String: String]
+
+    init(rawValue: String) {
+        self.rawValue = rawValue
+        var parsed: [String: String] = [:]
+        let separators = CharacterSet.whitespacesAndNewlines.union(CharacterSet(charactersIn: ";"))
+        for token in rawValue.components(separatedBy: separators) where !token.isEmpty {
+            guard let delimiterIndex = token.firstIndex(of: "=") else { continue }
+            let key = String(token[..<delimiterIndex])
+            let value = String(token[token.index(after: delimiterIndex)...])
+            parsed[key] = value
+        }
+        fields = parsed
+    }
+
+    subscript(key: String) -> String? {
+        fields[key]
+    }
+
+    var isOpened: Bool { fields["reader"] == "opened" }
+    var page: Int? { fields["page"].flatMap(Int.init) }
+    var display: String? { fields["display"] }
+    var toolbar: String? { fields["toolbar"] }
+    var highlights: Int? { fields["highlights"].flatMap(Int.init) }
+    var selection: Int? { fields["selection"].flatMap(Int.init) }
+    var href: String? { fields["href"] }
+    var progression: Double? { fields["progression"].flatMap(Double.init) }
+    var mode: String? { fields["mode"] }
+    var pagination: String? { fields["pagination"] }
+    var knownPages: Int? { fields["knownPages"].flatMap(Int.init) }
+    var knownChapters: Int? { fields["knownChapters"].flatMap(Int.init) }
+    var buildableChapters: Int? { fields["buildableChapters"].flatMap(Int.init) }
+    var avoidWidows: Int? { fields["avoidWidows"].flatMap(Int.init) }
+    var avoidOrphans: Int? { fields["avoidOrphans"].flatMap(Int.init) }
+}
+
+extension XCUIApplication {
+    func currentDemoReaderState() -> DemoReaderState? {
+        let state = staticTexts[IDs.demoReaderState]
+        guard state.exists else { return nil }
+        return DemoReaderState(rawValue: state.label)
+    }
+
+    @discardableResult
+    func waitForDemoReaderState(
+        timeout: TimeInterval = 8,
+        description: String,
+        where predicate: (DemoReaderState) -> Bool
+    ) -> DemoReaderState {
+        let stateElement = staticTexts[IDs.demoReaderState]
+        let deadline = Date().addingTimeInterval(timeout)
+        var lastState = DemoReaderState(rawValue: "<missing>")
+
+        while Date() < deadline {
+            if stateElement.exists {
+                lastState = DemoReaderState(rawValue: stateElement.label)
+                if predicate(lastState) {
+                    return lastState
+                }
+            }
+            RunLoop.current.run(until: Date().addingTimeInterval(0.1))
+        }
+
+        XCTFail("阅读器状态未满足条件: \(description)，当前：\(lastState.rawValue)")
+        return lastState
+    }
+}

ReadViewDemo/ReadViewDemoUITests/Helpers/XCUIApplication+Launch.swift

@@ -25,12 +25,15 @@ extension XCUIApplication {
     func waitForReader(timeout: TimeInterval = 12) -> XCUIElement {
         let state = staticTexts[IDs.demoReaderState]
         XCTAssertTrue(state.waitForExistence(timeout: timeout), "阅读器状态标签未出现")
-        XCTAssertTrue(state.label.contains("reader=opened"), "阅读器未进入 opened 状态：\(state.label)")
+        let parsed = DemoReaderState(rawValue: state.label)
+        XCTAssertTrue(parsed.isOpened, "阅读器未进入 opened 状态：\(state.label)")
         return state
     }
 
     func waitForReaderPage(_ pageNumber: Int, timeout: TimeInterval = 12) {
-        waitForReaderState(containing: "page=\(pageNumber)", timeout: timeout)
+        _ = waitForDemoReaderState(timeout: timeout, description: "page=\(pageNumber)") { state in
+            state.page == pageNumber
+        }
     }
 
     func showReaderChromeIfNeeded() {