fix(validate): check for [agents] instead of [agent] in HAND.toml (#15)

* fix(validate): check for [agents] instead of [agent] in HAND.toml

All 14 hands use [agents.main] (plural) for multi-agent config,
but the validator was checking for [agent] (singular), causing
all hands to fail validation.

* fix(routing): resolve 19 routing alias collisions

Agent is a sub-unit of hand, so hands take priority for routing.
Remove conflicting aliases from agent side when hand already owns them.

- analyst: remove data analysis, analyze data, dashboard (owned by hand/analytics)
- data-scientist: remove statistical analysis, forecast, prediction (owned by hand/analytics, hand/predictor)
- sales-assistant: remove prospecting, sales, pipeline (owned by hand/lead, hand/devops)
- devops-lead: remove incident response, kubernetes, terraform (owned by hand/devops)
- researcher: remove deep research, research, literature review (owned by hand/researcher)
- academic-researcher: remove literature review, systematic review (owned by hand/researcher)
- social-media: remove duplicate content calendar from weak_aliases
- hand/collector: remove competitive analysis (owned by hand/strategist)

agents/sales-assistant/agent.toml

@@ -9,11 +9,10 @@ tags = ["sales", "crm", "outreach", "pipeline", "prospecting", "deals"]
 aliases = [
   "sales outreach",
   "crm update",
-  "prospecting",
   "pipeline review",
   "deal tracking",
 ]
-weak_aliases = ["sales", "crm", "pipeline", "leads"]
+weak_aliases = ["crm", "leads"]
 
 [model]
 provider = "default"