openhuman/docs/tinyagents-full-migration-plan/03-context-cache/01-delete-legacy-context.md

03.1 — Delete superseded context reducers

tinyagents/middleware.rs doc-comments already note these were "effectively dead on the live loop" before being re-expressed as middlewares.

Current status: harness/compaction/cache_align.rs and the harness/compaction/mod.rs shim are deleted; the volatile-token detector now lives inside TinyAgents CacheAlignMiddleware.

Steps

1. context/microcompact.rs (269): deleted. The shared placeholder/default constants now live in context/mod.rs, and the live clearing logic is the TinyAgents MicrocompactMiddleware.
2. context/pipeline.rs (454) + context/guard.rs (236): deleted. The minimal usage/session-memory state now lives in context/stats.rs, and live compression uses ContextCompressionMiddleware + summarize.rs (SUMMARIZE_THRESHOLD_FRACTION preserves the 0.90 trigger).
3. harness/compaction/cache_align.rs (200) + compaction/mod.rs shim: superseded by CacheAlignMiddleware; directory deleted.
4. context/tool_result_budget.rs (172): deleted. The UTF-8-safe fallback truncation helper now lives beside action-workspace artifact preview handling; the live TinyAgents path uses ToolOutputMiddleware per-tool caps.
5. Legacy compaction-breaker fields in ContextStatsState / ContextStats: deleted after exact non-test call-path checks showed no production readers. The remaining stats projection is UI utilisation plus session-memory state.
6. Summarization provenance: ensure every compression emits AgentEvent::Compressed with SummaryRecord data (source ids, before/after token estimates) — wire ContextCompressionMiddleware:: records() into the run outcome/journal.

Deletions

• context/microcompact.rs, context/pipeline.rs, context/guard.rs, and harness/compaction/ are deleted.

Acceptance

• context/ line count drops ~1.2k; stats() UI footer parity test green; compression fires at 90% window on all three turn paths (existing summarize tests).