kmp-adapter-embedded 0.4.2

Embedded SQLite storage adapters for every KMP persistence port
Documentation
# kmp-adapter-embedded

[KMP](https://github.com/underpass-ai/kmp) is local-first agent memory that
preserves what happened, when and why. This crate supplies its embedded
storage adapters.

One `EmbeddedKernelStore` opens one data directory — a `FORMAT_VERSION` marker
next to `store/` — and implements every persistence port the kernel needs:
graph reads over materialized adjacency, node detail, the append-only context
event log, projection runtime state, snapshots and quality telemetry. No
server, no cluster, no daemon.

## One engine

The ports are written once against a small storage seam. Every new directory
is SQLite and records format 2. The crate does not link redb.

| Engine | `FORMAT_VERSION` | Store file | Availability |
| --- | --- | --- | --- |
| SQLite, WAL mode | 2 | `store/kernel.sqlite3` | active; always available |

Two agent hosts can open the same project memory, readers do not block the
writer, and a second writer waits for the commit lock. SQLite passes the full
conformance, `kill -9` recovery and two-process no-lost-events suites. See
ADR-018. A format-1 store is detected and rejected without touching its bytes;
export it with KMP 0.3.2, then import the portable bundle into current KMP.

Quality telemetry uses its own WAL journal at
`telemetry/quality.sqlite3`. Historical `quality.redb` files are left in place
as evidence but are not read by current binaries.

## What durability means here

Canonical memory commits use SQLite `synchronous=FULL` in WAL, so the crash
contract is explicit: nothing is lost beyond the in-flight event, and replay
applies nothing twice. The bounded telemetry journal uses periodic FULL
durability and a final durable checkpoint.

## Not a special case

The observable semantics are pinned by the conformance suite that also
certifies the in-memory store and the Neo4j / Valkey adapters. A store that
passes it behaves like the others or it does not ship.

## License

Apache-2.0.