删除深度重算引擎；修好回放视频每帧重开文件导致的无法播放，运输控制改到状态轨主按钮 - What: 1) 彻底删除深度重算引擎：shared/.../record/depth.py（DepthRecomputer/DepthResult）与 depth_backends.py（BoxReplay/FingerReplay）、其专属测试 test_depth_replay.py，record/__init__ 不再导出，playback.py::replay_warnings 不再报 depth_recomputed；apps/studio/replay.py 由 515 行瘦身为只做读盘+游标+视频帧+提示，回放视图的 2D 面板只提供「原始图像」；session.json 的 depth.replay 由 recompute 改为 none；删除 31 个只剩深度使用的文案键（depth_*/warn_state_*/warn_reset_*），warn_config_changed 与 warn_sdk_changed 改为描述"由视频重算"；ui_check 深度段、studio 两个深度用例、test_playback 三例、drive_shared 的 test_depth_replay 与 reproduce.py 的深度段一并清理（shared 套件 150→134 项）。2) 无法播放的根因是 RecordingReader.video_frame_at 每帧都 cv2.VideoCapture 重开并 seek：小片段已 ~10 ms/帧，1080p H.264 每次 seek 需从关键帧解码（上百 ms），而播放每 33 ms 要一帧且全在 UI 线程上，视频因此看着不动；改为按分段缓存解码器、顺序帧用 read() 步进（实测 10 ms → 0.5 ms/帧）、跳转才 seek，新增 RecordingReader.close() 释放。运输控制按用户建议上移到状态轨主按钮：toolbar.set_run_role("playback") 使回放视图的主按钮变成「▶ 回放」/「⏸ 暂停」（实时视图仍是「▶ 运行」），点按以 1× 推进游标（墙钟计时，漏拍不变慢）、到末尾自动停，拖动游标/框选/滚轮/拖总览条经 ForcePlotsPanel.timeline_taken_over 自动暂停，空格键同效；曲线表头不再放第二个播放按钮；按钮样式在回放角色下不再套用"停止"的红色语义。 - Why: 用户要求先清掉深度重算引擎、并反馈"现在无法播放视频"，建议把上方播放按钮在历史回放形式下改为回放。 - Verification: ui_check.py 554 项 0 失败（新增 seek<250ms/步进<60ms 的解码预算、回放按钮文字随播放/暂停切换、手动拖游标即暂停、切回实时视图按钮恢复运行、按深度视图已移除）；test_ui_smoke.py 71 项 0 失败；drive_shared.py 134 项 0 失败（深度引擎用例随代码删除）；locale_studio.py 262 键齐全、zh==en；reproduce.py 退出 0；.repro/probe_play.py 实测按「回放」后 0.75 s 内游标推进 0.689 s、面板 12/12 帧都在更新；两张复核图（回放视图的「▶ 回放」、实时视图的「▶ 运行」）。 - Not in this change: 录制文件格式与 CSV 列序不变（raw_*.mp4 与 forces.csv 继续一起写）；「由视频重算」复核模式保留（它复用实时管线，是有状态、只能顺序前进的一遍）。

shared/tests/test_playback.py

@@ -24,7 +24,6 @@ from orisys_app_shared.record import (
     RecordingReader,
     list_recordings,
 )
-from orisys_app_shared.record.depth import DepthRecomputer
 
 SCRATCH = Path(__file__).resolve().parent / "_scratch_playback"
 
@@ -219,60 +218,12 @@ def test_depth_policy_says_recompute_and_warns_about_drift(recording):
     # The config file on disk no longer matches what was recorded.
     codes = reader.replay_warnings(sdk_version="0.5.1")
     assert "config_changed" in codes
-    assert "depth_recomputed" in codes
 
     # Same SDK: no version warning.
     assert "sdk_changed" not in codes
     assert "sdk_changed" in reader.replay_warnings(sdk_version="9.9.9")
 
 
-def test_depth_recompute_preflight_states_why_it_cannot_run(recording):
-    reader = RecordingReader(recording)
-    recomputer = DepthRecomputer(reader)
-    try:
-        problem = recomputer.preflight()
-        assert problem in ("", "sdk_unavailable"), problem
-
-        # A recording with no config reference is refused, not guessed at.
-        missing = RecordingReader(recording)
-        missing._info = None  # noqa: SLF001 - force a re-read below
-        empty = SCRATCH / "empty"
-        empty.mkdir(exist_ok=True)
-        (empty / "forces.csv").write_text(
-            ",".join(("session_id", "frame_id", "t_rel_s", "FN_raw", "FX_raw", "FY_raw",
-                      "FN_N", "FX_N", "FY_N", "valid", "calibration_id")) + "\n",
-            encoding="utf-8",
-        )
-        (empty / "session.json").write_text(json.dumps({"depth": {"stored": False}}), encoding="utf-8")
-        bare = DepthRecomputer(RecordingReader(empty))
-        assert bare.preflight() in ("config_missing", "no_video", "sdk_unavailable")
-    finally:
-        recomputer.close()
-
-
-def test_depth_result_is_failed_not_blank_when_sdk_is_missing(recording):
-    """A missing SDK must produce an explicit error, never a stand-in image."""
-    saved = sys.modules.get("orisys")
-    blocker = types.ModuleType("orisys")
-    try:
-        # A module object with no Sensor/DEPTH surface: importing succeeds but
-        # nothing can be recomputed with it.
-        sys.modules["orisys"] = blocker
-        reader = RecordingReader(recording)
-        recomputer = DepthRecomputer(reader)
-        problem = recomputer.preflight()
-        assert problem in ("sdk_unavailable", ""), problem
-        if problem:
-            result = recomputer.depth_at(1.0)
-            assert not result.ok
-            assert result.depth is None
-            assert result.error
-    finally:
-        if saved is None:
-            sys.modules.pop("orisys", None)
-        else:
-            sys.modules["orisys"] = saved
-
 
 def test_list_recordings_finds_directories_newest_first(recording):
     second = SCRATCH / "zzz_later"