Add LLM Council agent and councilor subagents to hve-core

[andrewDoing]

Pull Request

Description

Adds an LLM Council agent that dispatches the same question package to GPT-5.4, Opus 4.6, and Gemini 3.1 Pro councilor subagents, then synthesizes consensus, disagreement, assumptions, uncertainty, and a recommended next step into one user-facing answer.

This contribution is scoped as a reusable decision-support pattern for hve-core rather than a broader orchestration platform. It keeps the first upstream cut focused on agent artifacts and discoverability updates.

Related Issue(s)

Closes #1326

Type of Change

Select all that apply:

Code & Documentation:

• Bug fix (non-breaking change fixing an issue)
• New feature (non-breaking change adding functionality)
• Breaking change (fix or feature causing existing functionality to change)
• Documentation update

Infrastructure & Configuration:

• GitHub Actions workflow
• Linting configuration (markdown, PowerShell, etc.)
• Security configuration
• DevContainer configuration
• Dependency update

AI Artifacts:

• Reviewed contribution with prompt-builder agent and addressed all feedback
• Copilot instructions (.github/instructions/*.instructions.md)
• Copilot prompt (.github/prompts/*.prompt.md)
• Copilot agent (.github/agents/*.agent.md)
• Copilot skill (.github/skills/*/SKILL.md)

Other:

• Script/automation (.ps1, .sh, .py)
• Other (please describe):

Sample Prompts (for AI Artifact Contributions)

User Request:

Compare two implementation approaches and tell me where the models agree, where they disagree, and what we should do next.

Execution Flow:

1. The LLM Council agent frames one shared question package.
2. The same package is sent to GPT-5.4, Opus 4.6, and Gemini 3.1 Pro councilor subagents.
3. Each councilor answers independently.
4. The LLM Council agent synthesizes consensus, disagreement, uncertainty, and a recommended next step.

Output Artifacts:

The agent returns one synthesized response rather than three separate answers. The response is expected to include a direct answer, consensus points, disagreement and uncertainty, model-by-model summaries, and a final recommendation.

Success Indicators:

The response clearly distinguishes agreement from disagreement, identifies uncertainty, and ends with an actionable recommendation instead of a raw transcript dump.

Testing

Validation has not been run yet in this PR creation flow.

Recommended validation before merge:

• npm run lint:md
• npm run spell-check
• npm run lint:frontmatter
• npm run validate:skills
• npm run lint:md-links
• npm run lint:ps
• npm run plugin:generate
• npm run docs:test

Checklist

Required Checks

• Documentation is updated (if applicable)
• Files follow existing naming conventions
• Changes are backwards compatible (if applicable)
• Tests added for new functionality (if applicable)

AI Artifact Contributions

• Used /prompt-analyze to review contribution
• Addressed all feedback from prompt-builder review
• Verified contribution follows common standards and type-specific requirements

Required Automated Checks

The following validation commands must pass before merging:

• Markdown linting: npm run lint:md
• Spell checking: npm run spell-check
• Frontmatter validation: npm run lint:frontmatter
• Skill structure validation: npm run validate:skills
• Link validation: npm run lint:md-links
• PowerShell analysis: npm run lint:ps
• Plugin freshness: npm run plugin:generate
• Docusaurus tests: npm run docs:test

Security Considerations

• This PR does not contain any sensitive or NDA information
• Any new dependencies have been reviewed for security issues
• Security-related scripts follow the principle of least privilege

Additional Notes

This PR adds a decision-support agent, not a replacement for RPI or PR Review workflows. The value is independent multi-model reasoning with explicit synthesis.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 87.65%. Comparing base (a18ab1a) to head (93cfe2d).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1327      +/-   ##
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+ Coverage   87.63%   87.65%   +0.01%     
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  Files          61       61              
  Lines        9328     9328              
==========================================
+ Hits         8175     8176       +1     
+ Misses       1153     1152       -1     

Flag	Coverage Δ
pester	85.22% <ø> (+0.01%)	⬆️

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see 2 files with indirect coverage changes

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