## 1. OpenSpec Artifacts

- [x] 1.1 Create proposal, design, spec, and tasks for durable metadata and log storage.
- [x] 1.2 Validate the change with `openspec validate implement-durable-platform-storage --strict`.

## 2. Durable Metadata Store

- [x] 2.1 Add platform storage configuration for backend, metadata path, data directory, and log directory.
- [x] 2.2 Implement a file-backed metadata store that persists repository snapshots and reloads them.
- [x] 2.3 Wire platform startup to use the configured durable store by default while keeping memory store available.
- [x] 2.4 Add tests proving metadata persistence and default admin idempotency across store reloads.

## 3. Segmented Log Body Store

- [x] 3.1 Add a `LogBodyStore` service boundary with append, duplicate lookup, and cursor query operations.
- [x] 3.2 Implement an in-memory log body store for tests and a file-segment log body store for durable startup.
- [x] 3.3 Refactor log ingest/query service code to use `LogBodyStore` and persist before advancing stream metadata.
- [x] 3.4 Add tests for duplicate acknowledgement and cursor query after log store reload.

## 4. Documentation And Verification

- [x] 4.1 Document storage backend choices and log storage guidance in platform protocol/API docs.
- [x] 4.2 Run `cd platform && go test ./...`.
- [x] 4.3 Run `scripts/check-structure.sh`.
- [x] 4.4 Run `openspec validate implement-durable-platform-storage --strict`.