Add more built-in agent roles (designer, lawyer, data-scientist, etc.)

[Dhwanil25]

Overview

Currently Agentis ships with these agent roles: researcher, analyst, writer, coder, reviewer, planner, summarizer.

This issue is to expand the role library with more domain-specific personas.

Suggested roles to add

Role	Description	Colour
designer	UI/UX, design systems, accessibility	#ec4899
lawyer	Legal analysis, contract review, compliance	#6366f1
data-scientist	Statistical analysis, ML reasoning, data interpretation	#06b6d4
marketer	Positioning, copy, GTM strategy	#f59e0b
product-manager	Requirements, prioritisation, roadmaps	#10b981
devops	Infrastructure, CI/CD, deployment	#64748b

Where to make changes

• src/lib/multiAgentEngine.ts — add new entries to AgentRole type and ROLE_COLORS
• The orchestrator prompt automatically picks roles from the type — no extra wiring needed

Good first issue

This is a great starting point — it only requires editing one file and adding entries to existing maps. No new infrastructure needed.