#372: make avro a core dependency, not optional

avro>=1.12 moved from [project.optional-dependencies] to dependencies.
With Avro as the default codec, the SDK is non-functional without it.
Docstring updated: avro is default, json is decode-only.

Author: durable-workflow-ops

pyproject.toml

@@ -32,12 +32,10 @@ classifiers = [
 ]
 dependencies = [
     "httpx>=0.27",
+    "avro>=1.12,<2",
 ]
 
 [project.optional-dependencies]
-avro = [
-    "avro>=1.12,<2",
-]
 dev = [
     "avro>=1.12,<2",
     "pytest>=8.0",

src/durable_workflow/serializer.py

@@ -6,11 +6,10 @@
 
 Supported codecs:
 
-- ``"json"`` — the blob is a UTF-8 JSON document. Default and always
-  available.
+- ``"json"`` — the blob is a UTF-8 JSON document. Supported for decoding
+  existing data only, not used for new workflows.
 - ``"avro"`` — the blob is a base64-encoded Avro generic-wrapper payload
-  (see :mod:`durable_workflow._avro`). Requires the optional ``avro``
-  extra: ``pip install 'durable-workflow[avro]'``.
+  (see :mod:`durable_workflow._avro`). Default for all new v2 workflows.
 """
 from __future__ import annotations