[BUG] tmpose recordings cannot be exported to Blender — pre-flight requires mediapipe_*.npy

Describe the bug REQUIRED_BLENDER_INPUT_FILES in freemocap/system/recording_status/recording_status.py is a flat list hardcoded to mediapipe_* filenames. Output files are prefixed with the detector that produced them, so a recording processed with rtmpose — the default detector — never satisfies the check and can never be exported.

To Reproduce Steps to reproduce the behavior:

1. Record a session with detectorType: "rtmpose" (the default)
2. Process it — output_data/ correctly fills with rtmpose_*.npy
3. Trigger Blender export (button, or POST /freemocap/blender/export)

Expected behavior The recording exports.

Actual FileNotFoundError listing missing mediapipe_body_3d_xyz.npy, mediapipe_right_hand_3d_xyz.npy, etc. — files that were never supposed to exist for this recording.

Environment Information: v2.0.0-alpha.20, Windows 11, 4 cameras, rtmpose

Additional context

• Reads as a processing failure rather than an export bug, so users likely re-run with MediaPipe instead of reporting.
• Not the same as #663 / #617 ("Blender file does not exist"), which are 1.x-era with different root causes (missing blender.exe, path issues).
• Present on main @ f16dd8bb. #846's legacy-filename fallback doesn't address it — the list is still mediapipe-only.