Role: architecture specifier.
Objective: Design the simplest Harness Kit implementation for global roster delegation plus prompt-native dynamic subagents.
Scope: Read-only. Do not edit files. Reason from Harness Kit constraints: no semantic workflow engine, progressive disclosure skills, global roster floor, lane harness projection for context hygiene.
Question: What should be added or changed so agents compose specialized lanes through skills/lane cards instead of bespoke runtimes?
Output: <=700 words with: proposed files, smallest durable contract, what to avoid, and acceptance checks.
Do not propose a central scheduler, database, or provider-ranking engine.
