[flows-tinyflows] flows bug: remember_keyed deletes the old value before the new write succeeds #49

Moved from tinyhumansai#8027, which is closed in favour of this issue. Part of tinyhumansai#8055.

remember_keyed (flows/memory_tools.rs:169-193) calls forget_matching on the key tag, then memory::ops::learn. If learn fails (engine/embedding error, timeout) the previous value is already gone. A digest flow storing sent_ids then recalls nothing next run and re-sends everything — the duplicate-send tinyhumansai#5173 was meant to prevent. Same path serves the memory[remember] node (flows/tinyflows/memory_adapter.rs:389).

Fix: learn first, then delete older ids under the key tag. Regression test with a failing learn.

The file stays in flows/ (decided in tinyhumansai#8000); #97 later dedups it onto upstream Confinement/MemoryOps — land this fix first so the dedup carries the corrected order.

Done when: each defect above has a regression test that fails on the unfixed code and passes after the fix. Gates: cargo check (root + crates/openhuman-app), pnpm rust:layout, node scripts/ci/check-feature-forwarding.mjs, pnpm debug rust flows, and the touched crates' tests. RPC namespace strings, model-facing tool names and DomainEvent variant names stay unchanged unless the issue says otherwise.

Agent brief

• Files to consider (paths under crates/openhuman-core/src/ unless rooted): flows/memory_tools.rs
• Research: feat(flows): per-flow memory namespace + post-run digest (flow:<id>) tinyhumansai/openhuman#5173.
• Workflow: an implementing-an-epic step.
• Subagent: systematic-debugger.
• Dependencies: none.

Parent: tinyhumansai#8055