feat: Add unique color identifiers to agent definitions

[JeremyDev87]

Purpose

Add a unique color to each agent definition so that when running multiple Claude Code sessions, agents are visually distinguishable at a glance via /color and /rename.

Changes

• packages/rules/.ai-rules/agents/*.json — Add color field to each agent definition (35 agents)
• packages/rules/.ai-rules/agents/README.md — Document the new color field in agent schema
• apps/mcp-server/ — Ensure get_agent_details exposes the color field

Acceptance Criteria

• All 35 agent JSON files have a unique color field
• Colors are distinct enough for quick visual identification
• get_agent_details MCP tool returns the color in response
• Agent README documents the color field
• Existing tests pass
• Can be merged independently

[JeremyDev87]

Technical Details

Exact Changes

1. Add "color" field to agent JSON schema — use hex codes or named colors (e.g., "#FF6B6B", "#4ECDC4")
2. Assign unique colors to all 35 agents grouped by category:
   • Planning agents: blue tones
   • Development agents: green tones
   • Review agents: orange/amber tones
   • Security agents: red tones
   • UX/Design agents: purple tones
3. Update packages/rules/.ai-rules/agents/README.md to document the color field
4. Verify apps/mcp-server/ get_agent_details returns the color field (it reads JSON directly, should work automatically)

Steps

1. Define color palette with 35 distinct colors
2. Add "color": "<hex>" to each agent JSON file
3. Update agent schema documentation in README
4. Test via MCP get_agent_details tool
5. Consider integration with Claude Code /color command for auto-assignment

References

• Claude Code /color and /rename commands for session identification
• Current agent schema has no display/visual fields