feat(studio-3d): 阶段 5 —— 发布保护（签名/可选加密/平台锁定）与性能长时报告

- What: 新增 `scene3d/protect.py`（封套 v2：Ed25519 签名 + 可选 AES-256-GCM，nonce/salt 每包唯一、
  元数据作 AAD、明文摘要进签名、KeyProvider 只问 get_content_key）与 `record/visualization3d.py`
  （session.json 的 visualization3d 块：写入版本化、读取时缺块=不支持）；`package.py` 支持 v2
  （payload=plain 仅签名 / aes-gcm 签名+加密）并继续读 v1，新增解压比上限与"写入后自读回"校验；
  `contracts.py` 新增 PlatformLock/PlatformInfo/check_platform_lock、Sealing、platform_mismatch 诊断码；
  `Scene3DView` 在装配前查 OS/架构、拿到 capabilities 后查图形半区，违反即撤下场景并在面板显示原因；
  工具 `compile_scene.py` 新增 --sign-key/--write-verify-key/--encrypt-key-id/--key-file/--lock-from-probe，
  `validate_scene.py` 新增 --key-file/--key-id/--verify-key/--require-signature（发布门禁），
  新增 `bench_scene.py`（p50/p95 分阶段 + --cpu-only + --vertices N + --package）与
  `soak_scene.py`（RSS 四分位速率 + 队列上界 + 抽稀采样）；两份报告落到 docs/architecture/。
- Why: 规格 §5.2 的保护目标是"提高复制成本"而不是"防提取"，所以要的是签名（来源）+ 可选认证加密（机密性）
  + 密钥隔离，而不是自制加密或把 ZIP 当加密；§12 的"包保护/性能/长时"三行需要可复现的数字与判定标准，
  而不是一次性的观感。平台锁定还必须只降级三维：锁定不通过时二维照常。
- Verification: shared 全量通过（新增 test_scene3d_protect.py 35 项：封套往返/篡改/密钥/锁定/记录块/
  compile→validate 端到端发布流程；test_scene3d_package.py 20 项含 v1↔v2 兼容）；apps/studio 全量通过
  （test_scene3d_view.py 30 项含锁定拒绝与 session.json 块）；ui_check 566 项 0 失败；locale_check 0 缺失；
  真实资产端到端：1032 顶点编译出 signed+sealed+locked 包（56 927 B 密文），validate --require-signature 退出 0，
  改一个字节退出 2；性能报告（perf-report-windows-dev.json）：1032 顶点 compose p50 0.50 ms（30 fps 上限内），
  20022 顶点/39480 三角形 compose p50 6.15 ms（约 33 ms 帧的 18%），采集线程 submit p95 < 0.4 ms（合成器被人为放慢到 50 ms）；
  长时报告（soak-report-windows-dev.json）：无窗口 10 min/60 fps 尾段 0.354 MB/min，GUI 4 min/30 fps 尾段 0.809 MB/min，
  队列上界（mailbox=1、单飞行合成）两者均成立。过程中修掉：GUI 进程里的合成器计时被 GIL/vsync 污染（98.8 ms vs 真值 6.1 ms）、
  跨线程读 last_stats 撕裂、key id 无 provider 时会静默写明文包、soak 工具自身记时间列表会无界增长、RSS 读取失败伪装成零增长、
  平台锁定不是终态诊断。
- Not in this change: ARM 板卡的能力报告与 2 小时门禁运行（按用户要求暂缓；命令与判定标准已写入阶段 5 文档）；
  GPU 显存随时间的测量（无可移植 API，报告说明渲染器缓冲估计恒定且更新路径不新建 GPU 对象）；
  `cryptography` 在此环境无法联网安装，本机验收用的是本机已有的 cp310 构建（pyproject 里已声明为可选 extra
  `protected-assets`）。

apps/studio/src/orisys_studio/scene3d/view.py

@@ -38,9 +38,11 @@ from orisys_app_shared.scene3d.contracts import (
     ExpectedGeometry,
     FieldDescriptor,
     FrameIdentity,
+    PlatformInfo,
     RenderStats,
     SceneAssets,
     SceneState,
+    check_platform_lock,
     diagnostic,
     validate_assets,
 )
@@ -170,6 +172,8 @@ class Scene3DView(QWidget):
         snapshot = self._make_snapshot(assets, expected)
         if snapshot is None:
             return False
+        if not self._lock_allows(assets):
+            return False
         self._assets = assets
         self._expected = expected
         self._snapshot = snapshot
@@ -180,6 +184,19 @@ class Scene3DView(QWidget):
             self._panel.set_scene(assets)
         return True
 
+    def _lock_allows(self, assets: SceneAssets) -> bool:
+        """The half of the platform lock that can be checked before a context exists.
+
+        Operating system and architecture are known now; the graphics fields only after
+        Qt has made a context, which is why the check is split (see
+        ``_check_lock_capabilities``). Refusing here is what keeps a package released
+        for one operating system from being drawn on another at all.
+        """
+        violations = check_platform_lock(assets.platform_lock, PlatformInfo.here())
+        for item in violations:
+            self._on_diagnostic(item)
+        return not violations
+
     def _make_snapshot(
         self, assets: SceneAssets, expected: Optional[ExpectedGeometry]
     ) -> Optional[Callable[[Any, FrameIdentity], Any]]:
@@ -373,13 +390,50 @@ class Scene3DView(QWidget):
         self.stateChanged.emit(state)
 
     def _on_capabilities(self, capabilities: Any) -> None:
-        if self._panel is not None and getattr(capabilities, "software_renderer", False):
+        software = bool(getattr(capabilities, "software_renderer", False))
+        if software and self._panel is not None:
             self._panel.set_diagnostic(
                 diagnostic(
                     "gl_unsupported",
                     "the OpenGL context is a software rasteriser: expect a slow view",
                 )
             )
+        self._check_lock_capabilities(capabilities)
+
+    def _check_lock_capabilities(self, capabilities: Any) -> None:
+        """The graphics half of the platform lock, checked the moment it is knowable.
+
+        A locked package whose lock this machine violates is *withdrawn*: the scene is
+        dropped and the pane shows the reason. Half a lock (the OS matched, the GPU did
+        not) is not a partial success — the package was qualified somewhere else.
+        """
+        assets = self._assets
+        if assets is None or assets.platform_lock is None:
+            return
+        if capabilities is None:
+            return
+        info = PlatformInfo.here(capabilities)
+        violations = check_platform_lock(assets.platform_lock, info)
+        if not violations:
+            return
+        for item in violations:
+            self._on_diagnostic(item)
+        self._withdraw_scene()
+
+    def _withdraw_scene(self) -> None:
+        """Drop the scene, keep the pane: a lock violation is not a crash."""
+        self._assets = None
+        self._snapshot = None
+        if self._coordinator is not None:
+            self._coordinator.close()
+        if self._widget is not None:
+            try:
+                self._widget.release_resources()
+            except Exception:  # noqa: BLE001 - withdrawal must not raise
+                logger.exception("releasing the GPU resources after a refusal failed")
+        if self._panel is not None:
+            self._panel.set_scene(None)
+        self._enabled = False
 
     def _on_descriptor(self, descriptor: Any) -> None:
         """The frame on screen changed what it claims to be.