fix: move coderd_default_agents_model state without a configured provider

[ethanndickson]

Problem

Upgrading from v0.0.23 to v0.0.24 with the documented migration

moved {
  from = coderd_default_agents_model.this
  to   = coderd_agents_default_model.this
}

fails deterministically at plan time:

Error: Unable to Move Default Agents Model State
The provider was not configured before Terraform attempted to move coderd_default_agents_model state.

Terraform Core calls the MoveResourceState RPC before ConfigureProvider (hashicorp/terraform#35922), so the mover's r.data is always nil — it errored on the nil check and otherwise depended on r.data.DefaultOrganizationID to fill id/organization_id. Every user of the moved block hit this; no configuration change could avoid it.

Fix

Make the state mover fully offline: carry over only the source state's model_id and write null id/organization_id. The first apply then adopts the configured organization in place:

• Update resolves the organization via resolveOrganizationID (prior state, then plan) instead of trusting prior state alone.
• organization_id uses the shared adoption-friendly RequiresReplaceIf (replace only when both state and config are non-null), so adoption is an in-place update while genuine org changes still replace.
• Read warns and preserves state instead of refreshing while organization_id is still null, mirroring the legacy handling in coderd_agents_model.

Regression coverage drives the migration through Terraform's real RPC lifecycle: a two-step resource.Test persists v0.0.23-schema state with an in-test legacy provider, then plans/applies the dogfood-shaped config (moved block, org data source) against the real provider factories, asserting in-place updates and final state. With the fix reverted, the test reproduces the dogfood error verbatim. Also records the lesson in AGENTS.md.

Refs coder/dogfood#453

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-08-31T11:52:03.532221Z	bbc265e	PR opened

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