chore(deps): bump agentex-sdk requires-python to >= 3.12

agentex/lib/* already uses `from typing import override` (3.12+) in 19
files. The 3.11 pin was inaccurate — `import agentex.lib.*` fails on
3.11 today. Bumping the pin to match reality.

agentex-sdk-client stays on >= 3.11 (zero 3.12-only imports).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: max-parke-scale

pyproject.toml

@@ -56,11 +56,13 @@ dependencies = [
     "opentelemetry-api>=1.20.0",
 ]
 
-requires-python = ">= 3.11,<4"
+# Bump from 3.11 to match the de-facto floor: agentex/lib/* already uses
+# `from typing import override` (19 files) which is 3.12+ only. The slim
+# agentex-sdk-client keeps 3.11 support — it has zero 3.12-only imports.
+requires-python = ">= 3.12,<4"
 classifiers = [
   "Typing :: Typed",
   "Intended Audience :: Developers",
-  "Programming Language :: Python :: 3.11",
   "Programming Language :: Python :: 3.12",
   "Programming Language :: Python :: 3.13",
   "Programming Language :: Python :: 3.14",