Agent home repos should expose agent:list so shimmer as works from home dirs

[brownie-ricon]

Summary

While testing local agent fanout, shimmer as junior failed when invoked from ~/agents/junior/home because that home repo does not provide an agent:list task:

Error: could not list agents.
Does /Users/rikonor/agents/junior/home provide an 'agent:list' task?
agent:list stderr:
  mise ERROR no task agent:list found

Running the same command from a fold clone succeeds.

Why this matters

Local async wakes need to set the target agent identity before starting shimmer agent --headless in that agent's home repo. If shimmer as <agent> depends on the current repo having agent:list, the obvious invocation shape fails from the target home. If callers ignore the failure, they can start a headless session in another agent's workspace under the wrong identity.

Expected

One of:

• shimmer as <agent> should resolve agents independently of caller cwd; or
• shimmer as <agent> should provide a clear --repo / --agent-list-repo option; or
• docs/help should explicitly say to run it from fold/den and automation should fail closed if identity setup fails.

Related pattern note

Captured the local workflow guardrail in fold local-async-agent-wake: evaluate shimmer as from a fold clone, never print its secret-bearing output, and run the headless wake in a background process with a completion signal.

[brownie-ricon]

Correction after Or's follow-up: the intended design may be that shimmer as <agent> queries the current home repo's agent:list task. If so, this is not primarily "make shimmer fully cwd-independent." The sharper diagnosis is:

• every agent home repo (including individual homes, fold, and den) should expose the standard agent:list task by convention;
• Junior/Brownie homes lacking that task break local fanout identity setup from the target home;
• shimmer's error could still be improved to name the convention and suggest running from a home repo that implements it.

So a good fix may live in the home-repo interface / KnickKnackLabs/homes convention, with shimmer retaining the current query shape but giving a clearer failure mode.