docs(cosmos3): add hand pose forward dynamics example

[hans-yang-tps]

Description

Add a Cosmos3 Nano functional-dexterity hand-pose inference example to the Action cookbook, covering both Cosmos Framework and vLLM-Omni execution paths.

Depends on NVIDIA/cosmos-framework#71 for the public human hand-pose dataset definition.

Changes

• Add one self-contained validation episode for the task unscrew nut with screwdriver as a LeRobot asset with one Parquet file and one MP4 file.
• Reindex the public-facing episode metadata and remove source user IDs, original episode IDs, and private filesystem paths.
• Add a hand-pose action-definition section to the Action cookbook README.
• Add matching hand-pose setup, inference, and preview sections to run_fd_with_cosmos_framework.ipynb and run_fd_with_vllm.ipynb.

Validation

• Selected the episode from the validation split, not the training split.
• Asset integrity: 1,440 video frames at 30 FPS, 832x480; one matching Parquet episode.
• Cosmos Framework notebook: 45 cells, 18 code cells, zero errors, and zero unexecuted non-empty code cells.
• vLLM-Omni notebook: 38 cells, 17 code cells, zero errors; only the two pre-existing empty placeholder cells were unexecuted.
• Hand-pose output through each path: 17 frames at 15 FPS, 832x480.
• Notebook sources contain no stored outputs or execution counts.

[hans-yang-tps]

Need Michael(Zhengyu) Huang's help to review it.

[michaelhu-hash]

We should better also update the readme in here to include the hand pose eg.

cosmos/README.md

Lines 748 to 749 in 274e84e

| Forward dynamics with Cosmos Framework | Generator | Forward dynamics: action-conditioned future-observation prediction for AV, DROID, and UMI, through the `cosmos_framework.scripts.inference` entrypoint. | [Notebook](cookbooks/cosmos3/generator/action/run_fd_with_cosmos_framework.ipynb) | [](https://nbviewer.org/github/nvidia/cosmos/blob/main/cookbooks/cosmos3/generator/action/run_fd_with_cosmos_framework.ipynb) |

| Forward dynamics with vLLM-Omni | Generator | Forward dynamics: action-conditioned future-observation prediction for AV, DROID, and UMI, against an OpenAI-compatible vLLM-Omni server. | [Notebook](cookbooks/cosmos3/generator/action/run_fd_with_vllm.ipynb) | [](https://nbviewer.org/github/nvidia/cosmos/blob/main/cookbooks/cosmos3/generator/action/run_fd_with_vllm.ipynb) |

[hans-yang-tps]

Also removed Mecka keywords.

[lfengad]

Also, could we make a test run regarding all these newly added code/notebooks, to execute from a clean env for a further verification of the updated workflow? THX!

[lfengad]

The vfm related folder already renamed to generator, here might need corresponding change?