Implement prompts JSON CLI workflow

[jasonsky-pub]

Description

Adds a prompt JSON workflow for project init and project update.

This change introduces:

• --print-prompts-json to export prompt requirements as JSON without modifying project state
• --prompts-json-file and --prompts-json-stdin to supply prompt answers non-interactively
• dedicated prompt document parsing, export, usage tracking, and warning paths
• helper extraction to keep the normal runtime walk behavior stable while isolating prompt JSON concerns
• focused regression and feature coverage for prompt export/import and existing runtime behavior

Related Issue

N/A

Motivation and Context

This allows machine-driven OpenPlate runs to discover required prompt inputs ahead of time, fill them in externally, and execute init/update without interactive prompting.

The implementation keeps JSON-input mode on the normal runtime walk, while --print-prompts-json uses a read-only collector path so prompt discovery does not mutate project state.

How Has This Been Tested?

Ran:

• pytest tests/test_existing_runtime_regressions.py tests/test_prompt_json_cli.py tests/test_project_init_source_urls.py tests/test_prompt_document.py -m unit -n 0

Validated areas:

• prompt JSON export
• prompt JSON import from file and stdin
• duplicate and omitted-value validation
• ignored template and unused parameter warnings
• blank string handling
• unresolved required prompt failures
• template command confirmation failure paths in JSON mode
• regression coverage for existing runtime control flow

Screenshots

N/A

Types of Changes

Put an x in all boxes that apply.

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that changes existing behavior)
• Documentation update
• Maintenance or refactor

Checklist

Put an x in all boxes that apply.

• My code follows the style of this project.
• My change requires documentation updates.
• I have updated the documentation accordingly.
• I have read CONTRIBUTING.md.
• I have added or updated tests to cover my changes.
• All relevant new and existing tests passed.

Declaration

I confirm that this contribution is made under the Apache 2.0 license and that I have the authority necessary to make this contribution on behalf of its copyright owner.

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