ops: migrate legacy event sequences safely

deploy/DEPLOYMENT.md

@@ -41,3 +41,28 @@ Verify the coordinator at `GET /v1/admin/diagnostics` with the normal admin
 credential: its `build` object is the coordinator provenance. `GET
 /v1/federation/workers` shows every worker's `build`, supported projects, and
 worker-local health without SSH.
+
+For the Docker coordinator deployment, provide the same provenance as build
+arguments (the Dockerfile intentionally cannot read `.git` from its build
+context):
+
+```sh
+revision=$(git rev-parse HEAD)
+build_time=$(date -u +%Y-%m-%dT%H:%M:%SZ)
+dirty=false; test -z "$(git status --porcelain)" || dirty=true
+docker compose build \
+  --build-arg BUILD_REVISION="$revision" \
+  --build-arg BUILD_TIME="$build_time" \
+  --build-arg BUILD_DIRTY="$dirty" \
+  orchestra-api
+docker compose up -d --no-deps orchestra-api
+```
+
+If a pre-v2 event log has the historical repeated-`seq=1` prefix, the current
+coordinator intentionally refuses to replay it. Stop every coordinator using
+the data directory and run the explicit, backup-preserving migration before
+deploying the current image:
+
+```sh
+orchestra-migrate -data /var/lib/orchestra/data -confirm
+```