Track agent template source/version and support template upgrades

[chubes4]

Problem

Agents can be created and configured, but there is no strong relationship between a local agent and the template or bundle version it came from.

Without that relationship, default agent behavior cannot be upgraded safely.

Desired shape

Agents installed from templates/bundles should track their source.

Track:

• source bundle/template slug
• source bundle/template version
• installed artifact hashes for instructions/tool policy/default settings
• local modification state
• template upgrade availability

Acceptance criteria

• An agent can report the bundle/template and version it was installed from.
• Local modifications to instructions/tool policy/default settings are detectable.
• Clean template-owned agent artifacts can auto-update.
• Modified agent artifacts stage a PendingAction for approval.
• User-owned memory/content is not overwritten by template upgrades.

Context

For a WooCommerce brain, the agent identity should remain one stable local agent while its default instructions, tool policy, and pipelines can be upgraded over time.

AI assistance

• AI assistance: Yes
• Tool(s): OpenCode (GPT-5.5)
• Used for: Drafting the issue from product/design discussion; Chris remains responsible for prioritization and implementation.

[chubes4]

Partially shipped in Data Machine v0.97.1. PR #1549 added AgentTemplateMetadata and manifest source fields (bundle_slug, bundle_version, source_ref, source_revision). PR #1553 stores datamachine_bundle metadata on imported agents and the agent-bundle CLI can report installed bundle slug/version/status. What remains: template-owned agent artifacts such as instructions, tool policy, and defaults do not yet have full current-state collectors/apply writers, and template upgrade availability/local override UX is still not complete. Leaving open for the upgrade semantics around template-owned agent behavior.