#3206 The managed AGENTS.md template shouldn't charge a no-op 'swamp model search --json' to every session

The managed ## Getting Started section of the agent instructions template instructs every agent to run swamp model search --json at the start of every conversation, and to invoke the onboarding skill if it returns nothing:

**IMPORTANT:** At the start of every conversation, run
``swamp model search --json``. If no models are returned (empty result), you MUST
immediately invoke the `swamp-getting-started` skill before doing anything else.
This walks new users through an interactive onboarding tutorial.

If models already exist, start by using the `swamp` skill to work with
swamp models.

This is a permanent no-op on any instance that already has models provisioned — which is every instance after the first session. An agent that has seen the command return results learns it carries no information, and rational agents (human and AI) skip instructions that provide none. The check only ever trips on a fresh install, yet it is charged to every session.

The section is regenerated by swamp repo upgrade, so local deletion is not a fix. There is also no session-start hook surface in agent runtimes to wire detection logic to, so the instruction can only be satisfied by agent goodwill.

Request: drop the unconditional check from the template, or gate it so it only fires when no models are present. Detecting "fresh install" can happen at the point where the agent is actually starting work — the check does not need to be a session-start event, it just needs to not be a permanent no-op.

Related: Lab #3126 (closed as "not a bug" — the closure reframed this as agent compliance rather than a template defect, but the underlying problem stands: the template forces a no-op instruction onto every session and cannot be locally fixed).

Credit: please list me as co-author on the generated PR if one ships.