# BAT-015 Implementation

## Code changes

- `jarca_ledger_mcp/adapters/mcp/server.py`
  - Added `McpRuntimeConfig` dataclass.
  - Added env parsing for `JARCA_MCP_TRANSPORT`, `JARCA_MCP_HOST`, `JARCA_MCP_PORT`, `JARCA_MCP_STREAMABLE_HTTP_PATH`, `JARCA_MCP_SSE_PATH`, `JARCA_MCP_MESSAGE_PATH`, `JARCA_MCP_STATELESS_HTTP`.
  - Instantiates FastMCP with configured host/port/path values.
  - Calls `mcp.run(transport=_runtime_config.transport)`.
- `tests/test_mcp_http_runtime.py`
  - Added config tests for default stdio, streamable-http env, and invalid transport rejection.

## Deployment files

- `Dockerfile`
  - Builds `jarca-ledger:latest` from `python:3.12-slim`.
  - Installs `.[dashboard]` dependencies.
  - Exposes port 8000 and runs `jarca-ledger-mcp`.
  - Adds TCP healthcheck against `127.0.0.1:${JARCA_MCP_PORT}`.
- `.dockerignore`
  - Excludes `.env`, DBs, financial source files, tests/docs/scripts not needed in image, and local artifacts.
- `docker-compose.yml`
  - Defines `container_name: jarca-ledger`.
  - Maps `8000:8000`.
  - Mounts `/volume1/docker/jarca-ledger/data:/data`.
  - Sets streamable-http MCP env.
  - Uses `restart: unless-stopped`.

## Data migration implementation

1. Created a consistent source snapshot inside the old `jarca` container using SQLite backup API.
2. Copied snapshot to the host temp path.
3. Backed up the initial empty `jarca-ledger` DB under `/data/backups/pre_migration_empty_20260705152129.sqlite3`.
4. Stopped `jarca-ledger`, removed WAL/SHM sidecars, copied the snapshot to `/data/ledger.sqlite3`, normalized permissions, and restarted.
5. Waited for Docker health to become `healthy`.

## Documentation changes

- Added `docs/runbooks/docker-network-mcp-deploy.md`.
- Added this StagePilot post-implementation trace: dcy-013, REQ-019, BAT-015.
- Updated `docs/project-structure.md` and `docs/runtime-flows.md` to include Docker/network MCP runtime.