Parse terminal JSON action blobs into structured tool calls

Several terminal-style datasets preserve assistant JSON action blobs as plain message text. These often include fields such as analysis, plan, commands, and task_complete. A stricter standardized form would put analysis/plan in message or reasoning fields, convert commands to terminal tool calls, and convert completion signals to finish.

Known affected families include LiteCoder terminal, Nemotron terminal, OpenThoughts-Agent, and possibly other terminal traces with the same JSON response format.

Acceptance criteria:

• Add a reusable parser for the terminal JSON response format.
• Convert command batches to structured terminal tool calls when the JSON parses safely.
• Preserve original raw text/provenance in extra when parsing succeeds.
• Regenerate affected samples and validate them.

Start by locating the existing dataset parsing or normalization entry point and the representations used for terminal and finish calls. Implement the reusable parser for the stated JSON fields, then regenerate LiteCoder terminal, Nemotron terminal, and OpenThoughts-Agent samples and validate structured calls plus preserved raw provenance.