chore(flink): align the container runtime with the pinned 2.3.0 extra (#168)

pyproject pinned apache-flink==2.3.0 while every container ran 2.2.1
(flink_jobs image ARG + both flink:2.2.1-java17 cluster images), so local
development could exercise behaviour absent from the deployed minor.

Runtime moves to 2.3.0. The Kafka connector stays 5.0.0-2.2: the
externalised connector is versioned <connector>-<flink minor> and no -2.3
artifact is published; @public API is stable within a Flink major, and
flink-smoke submits the real job to a real cluster on every PR, so the
pairing is asserted, not assumed. Documented at the ARG.

docs/architecture.md Technology Choices reads Flink 2.3. Historical
records keep the version they were measured on.

Closes F2 of the 07.07 audit (plan_07_07_26.md, S2).

Co-authored-by: JuliaEdom <uedomskikh@gmail.com>
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: 3 people

CHANGELOG.md

@@ -4,6 +4,32 @@ All notable changes to AgentFlow are documented in this file.
 
 ## [Unreleased]
 
+### Changed — one Flink version across pip extra and container runtime (audit 07.07 F2)
+
+- **The Docker runtime moves 2.2.1 → 2.3.0**, matching the `[flink]` extra
+  (`apache-flink==2.3.0`, bumped in #87 and smoke-validated since): the
+  `flink_jobs` image ARG (`FLINK_VERSION`, which also drives the pip install
+  and the `flink-s3-fs-hadoop` plugin symlink) and both official cluster
+  images in `docker-compose.yml` (`flink:2.3.0-java17`). Developing locally
+  against a 2.3.0 PyFlink while the cluster ran 2.2.1 could surface behaviour
+  that did not exist on the deployed minor; the two lines are now one.
+- **The Kafka connector stays `flink-sql-connector-kafka-5.0.0-2.2`** — the
+  externalised connector is versioned `<connector>-<flink minor>` and no
+  `-2.3` build is published. Flink keeps `@Public` API stable within a major,
+  so the 2.2 artifact runs on a 2.3 cluster; the Dockerfile says so, and
+  `flink-smoke` submits `stream_processor.py` to a real Kafka+MinIO+Flink
+  cluster on every PR, so the combination is asserted rather than assumed.
+- `docs/architecture.md` Technology Choices now reads Flink 2.3. Historical
+  records (CHANGELOG entries, `docs/perf/freshness-realpath-2026-06-30.md`)
+  keep the version they were measured on.
+
+### Changed — the published SDK is under the same lint gate as `src/` (audit 07.07 F1)
+
+- `ci.yml` runs `ruff check` and `ruff format --check` over `sdk/` as well;
+  the one-off reformat touched `async_client.py`, `cli.py`, `client.py`
+  (line-collapse only). `make lint` / `make format` now cover
+  `src/ tests/ scripts/ sdk/`, so local and CI agree.
+
 ## [2.0.0] - 2026-07-06
 
 ### Fixed — single-container demo deploys pin the DuckDB serving backend (G2 S7, 2026-07-06)

docker-compose.yml

@@ -47,7 +47,7 @@ services:
 
   # ── Flink ─────────────────────────────────────────────────────
   flink-jobmanager:
-    image: flink:2.2.1-java17
+    image: flink:2.3.0-java17
     ports:
       - "8081:8081"
     command: jobmanager
@@ -73,7 +73,7 @@ services:
       retries: 5
 
   flink-taskmanager:
-    image: flink:2.2.1-java17
+    image: flink:2.3.0-java17
     depends_on:
       flink-jobmanager:
         condition: service_healthy

docs/architecture.md

@@ -95,7 +95,7 @@ See [Architecture Decision Records](decisions/) for detailed trade-off analysis.
 |-----------|--------|-----------|-------------------|
 | Streaming | Kafka 3.7 (KRaft) | Pulsar | Ecosystem maturity, MSK managed service |
 | CDC capture | Debezium + Kafka Connect | Python-native connectors | Mature Postgres/MySQL CDC, built-in offsets/schema history, one ops model |
-| Processing | Flink 2.2 | Spark Structured Streaming | True event-time, lower latency, native watermarks |
+| Processing | Flink 2.3 | Spark Structured Streaming | True event-time, lower latency, native watermarks |
 | Storage | Iceberg 1.5 | Delta Lake | Vendor-neutral, hidden partitioning, time-travel |
 | Local query | DuckDB | SQLite | Columnar, fast analytics, Iceberg support |
 | Orchestration | Dagster | Airflow | Software-defined assets, better testing, type safety |

src/processing/flink_jobs/Dockerfile

@@ -1,7 +1,11 @@
 FROM python:3.11-slim-bookworm@sha256:721dc13fd1be0a771e54b72097634291d628d0007dee9da777e2ce676a9c998f
 
-ARG FLINK_VERSION=2.2.1
+ARG FLINK_VERSION=2.3.0
 ARG SCALA_VERSION=2.12
+# The externalised Kafka connector is versioned <connector>-<flink minor> and
+# its newest published build is 5.0.0-2.2 — there is no -2.3 artifact. Flink
+# keeps @Public API stable inside a major, so the 2.2 build runs on a 2.3
+# cluster; flink-smoke submits the real job against it to keep that honest.
 ARG PYFLINK_KAFKA_JAR_VERSION=5.0.0-2.2
 
 RUN apt-get update \