Migrate DailyMemoryTask to Agents API memory compaction contract

[chubes4]

Problem

DailyMemoryTask currently owns prompt construction, parsing, conservation checks, and deterministic overflow behavior directly. Agents API now has conversation compaction and should grow generic memory compaction primitives. Once those land, Data Machine should consume the substrate instead of carrying bespoke compaction mechanics.

Goal

Migrate Daily Memory compaction to the Agents API generic memory/markdown compaction contract when available.

Scope

• Keep Data Machine responsible for:
  • reading/writing MEMORY.md
  • writing daily archive files
  • scheduling system tasks
  • selecting provider/model via existing settings
  • calling Data Machine RequestBuilder or other runtime as summarizer
• Move/reuse from Agents API:
  • item normalization
  • markdown section boundaries
  • conservation metadata/checks
  • lifecycle events
  • deterministic overflow strategy

Acceptance Criteria

• DailyMemoryTask delegates compaction planning/transformation to Agents API primitives.
• Existing normal AI compaction behavior remains functionally equivalent.
• Existing overflow behavior remains fail-safe and preserves archived content verbatim.
• Tests cover moderate memory compaction, conservation failure, and runaway overflow.

Dependencies

• Automattic/agents-api generic compaction item contract.
• Automattic/agents-api conservation metadata/checks.
• Automattic/agents-api deterministic overflow strategy.
• Automattic/agents-api markdown-section adapter.

[chubes4]

Current status after Agents API substrate wave

This remains real backlog; leaving open.

Updated dependency status:

• Agents API main now has the generic compaction primitives this issue was waiting on:
  • AgentsAPI\AI\AgentCompactionItem
  • AgentsAPI\AI\AgentConversationCompaction
  • AgentsAPI\AI\AgentMarkdownSectionCompactionAdapter
• Data Machine origin/main still owns DailyMemoryTask compaction directly in inc/Engine/AI/System/Tasks/DailyMemoryTask.php.
• The current implementation still includes local conservation/overflow behavior and the private splitMemorySectionsForOverflow() helper, with coverage in tests/daily-memory-conservation-smoke.php and tests/daily-memory-overflow-split-smoke.php.

So this issue should now move from "blocked on Agents API primitives" to "consume the landed primitives in DailyMemoryTask."

Current acceptance criteria should remain:

• Use Agents API compaction item/markdown adapter contracts for section planning/transformation.
• Keep Data Machine responsible for reading/writing MEMORY.md, daily archive persistence, scheduling, model/provider selection, and the summarizer call.
• Preserve fail-closed conservation behavior and verbatim archive retention.
• Keep the existing moderate compaction, conservation failure, and runaway overflow coverage green.

Related narrower issue:

• Route Daily Memory overflow fallback through Agents API strategy #1708 tracks the deterministic overflow/archive fallback slice.

AI assistance

• AI assistance: Yes
• Tool(s): OpenCode (GPT-5.5)
• Used for: Auditing Agents API main, Data Machine main, and current DailyMemoryTask/test ownership, then drafting this updated issue status. Chris remains responsible for review and final issue management.