feat(sdk): OTA 升级流程对齐 expo + 拆 extension 文件分层 + 秘钥本地化

主要改动：
- 新增 fetchLatestFirmware/upgradeFirmware/tryReportPendingUpgrade
  三段 OTA 接口，对齐 expo bindDeviceWithOrchestration 行为
- bind 仅做硬绑+getVersion，软绑/对账上报/拉最新固件搬到
  fetchLatestFirmware 内部串；软绑失败自动硬解回滚
- UpgradeRecord 复合主键 (sn, firmwareId) 持久化 + sn 级 in-flight 互斥
- DuooomiBleSDKDelegate 新增 didUpdateUpgradeRecords，集成方
  可观察对账上报结果（reported/outcome 状态）
- DuooomiBleSDK 主类按职责拆 5 个 extension 文件，公开 API 不变
- TargetFirmware 简化为只取必要字段 + 新增 forceUpgrade
- scanNamePrefix 改为必填 String
- demo 秘钥移至本地 DemoSecrets.swift (gitignored)
- README 重写：完整 OTA 流程示例 + 上报状态判定表

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Tests/DuooomiBleSDKTests/UpgradeRecordStoreTests.swift

@@ -0,0 +1,168 @@
+import XCTest
+@testable import DuooomiBleSDK
+
+/// 与 RN `bleStore.upgradeRecords` 行为对齐的关键回归测试。
+final class UpgradeRecordStoreTests: XCTestCase {
+
+    private var defaults: UserDefaults!
+    private let suiteName = "duooomi.test.upgradeRecord"
+
+    override func setUp() {
+        super.setUp()
+        defaults = UserDefaults(suiteName: suiteName)
+        defaults.removePersistentDomain(forName: suiteName)
+    }
+
+    override func tearDown() {
+        defaults.removePersistentDomain(forName: suiteName)
+        defaults = nil
+        super.tearDown()
+    }
+
+    private func makeStore() -> UpgradeRecordStore {
+        UpgradeRecordStore(defaults: defaults)
+    }
+
+    private func sample(sn: String = "A123456", firmwareId: String = "fw-1", triggeredAt: Int64? = nil) -> UpgradeRecord {
+        UpgradeRecord(
+            sn: sn,
+            firmwareId: firmwareId,
+            fromVersion: "1.0.0",
+            targetVersion: "1.1.0",
+            triggeredAt: triggeredAt ?? UpgradeRecordStore.nowMillis()
+        )
+    }
+
+    private func wait(_ s: TimeInterval = 0.1) {
+        let exp = expectation(description: "delay")
+        DispatchQueue.main.asyncAfter(deadline: .now() + s) { exp.fulfill() }
+        wait(for: [exp], timeout: s + 1)
+    }
+
+    // MARK: - upsert 复合主键
+
+    func testUpsertAddsNewRecord() {
+        let store = makeStore()
+        store.upsert(sample())
+        wait()
+        XCTAssertEqual(store.all.count, 1)
+        XCTAssertEqual(store.all.first?.firmwareId, "fw-1")
+    }
+
+    func testUpsertSameKeyReplacesAndResetsReportedFlag() {
+        let store = makeStore()
+        let r1 = UpgradeRecord(
+            sn: "A1", firmwareId: "fw-1",
+            fromVersion: "1.0.0", targetVersion: "1.1.0",
+            triggeredAt: 1000, reported: true, reportedAt: 2000, outcome: .success
+        )
+        store.upsert(r1)
+        wait()
+
+        // 同 (sn, firmwareId)，新 record 覆盖且 reported=false（重试场景）
+        let r2 = UpgradeRecord(
+            sn: "A1", firmwareId: "fw-1",
+            fromVersion: "1.0.0", targetVersion: "1.2.0",
+            triggeredAt: 5000
+        )
+        store.upsert(r2)
+        wait()
+
+        XCTAssertEqual(store.all.count, 1)
+        let only = store.all[0]
+        XCTAssertEqual(only.targetVersion, "1.2.0")
+        XCTAssertFalse(only.reported)
+        XCTAssertNil(only.reportedAt)
+        XCTAssertNil(only.outcome)
+    }
+
+    func testUpsertDifferentFirmwareIdAppends() {
+        let store = makeStore()
+        store.upsert(sample(firmwareId: "fw-1"))
+        store.upsert(sample(firmwareId: "fw-2"))
+        wait()
+        XCTAssertEqual(store.all.count, 2)
+    }
+
+    func testUpsertEmptySnIgnored() {
+        let store = makeStore()
+        store.upsert(sample(sn: ""))
+        wait()
+        XCTAssertEqual(store.all.count, 0)
+    }
+
+    // MARK: - pending 排序
+
+    func testPendingExcludesReportedAndSortsAsc() {
+        let store = makeStore()
+        store.upsert(UpgradeRecord(sn: "A", firmwareId: "fw-old", fromVersion: "1.0", targetVersion: "1.1", triggeredAt: 100))
+        store.upsert(UpgradeRecord(sn: "A", firmwareId: "fw-new", fromVersion: "1.0", targetVersion: "1.2", triggeredAt: 300))
+        store.upsert(UpgradeRecord(sn: "A", firmwareId: "fw-mid", fromVersion: "1.0", targetVersion: "1.15", triggeredAt: 200))
+        store.upsert(UpgradeRecord(sn: "B", firmwareId: "fw-other", fromVersion: "1.0", targetVersion: "1.1", triggeredAt: 50))
+        wait()
+
+        let pending = store.pending(sn: "A")
+        XCTAssertEqual(pending.map { $0.firmwareId }, ["fw-old", "fw-mid", "fw-new"])
+
+        store.markReported(sn: "A", firmwareId: "fw-old", outcome: .success)
+        wait()
+        XCTAssertEqual(store.pending(sn: "A").map { $0.firmwareId }, ["fw-mid", "fw-new"])
+    }
+
+    // MARK: - markReported
+
+    func testMarkReportedSetsFlagAndOutcome() {
+        let store = makeStore()
+        store.upsert(sample())
+        wait()
+        store.markReported(sn: "A123456", firmwareId: "fw-1", outcome: .versionMismatch)
+        wait()
+
+        let r = store.all[0]
+        XCTAssertTrue(r.reported)
+        XCTAssertNotNil(r.reportedAt)
+        XCTAssertEqual(r.outcome, .versionMismatch)
+    }
+
+    func testMarkReportedTtlExpiredOutcomeNil() {
+        // RN 行为：TTL 过期 → markReported(null)，保留为审计轨迹
+        let store = makeStore()
+        store.upsert(sample())
+        wait()
+        store.markReported(sn: "A123456", firmwareId: "fw-1", outcome: nil)
+        wait()
+        let r = store.all[0]
+        XCTAssertTrue(r.reported)
+        XCTAssertNil(r.outcome)
+    }
+
+    // MARK: - sn 互斥
+
+    func testTryAcquireReturnsFalseWhileHeld() {
+        let store = makeStore()
+        XCTAssertTrue(store.tryAcquire(sn: "A1"))
+        XCTAssertFalse(store.tryAcquire(sn: "A1"))
+        // 不同 sn 互不影响
+        XCTAssertTrue(store.tryAcquire(sn: "B1"))
+    }
+
+    func testReleaseAllowsReacquire() {
+        let store = makeStore()
+        XCTAssertTrue(store.tryAcquire(sn: "A1"))
+        store.release(sn: "A1")
+        wait()
+        XCTAssertTrue(store.tryAcquire(sn: "A1"))
+    }
+
+    // MARK: - 持久化 round-trip
+
+    func testRecordsPersistAcrossInstances() {
+        let store1 = makeStore()
+        store1.upsert(sample())
+        wait()
+
+        let store2 = UpgradeRecordStore(defaults: defaults)
+        XCTAssertEqual(store2.all.count, 1)
+        XCTAssertEqual(store2.all[0].firmwareId, "fw-1")
+    }
+}