Python: bump package versions for 1.4.0 release (#5872)

* fixes

* fixes

* Python: bump package versions for 1.4.0 release

Cuts the python-1.4.0 release. MINOR bump on the released cohort
(agent-framework, agent-framework-core, agent-framework-openai,
agent-framework-foundry: 1.3.0 -> 1.4.0), driven by breaking changes
in experimental skills API and new features. All 21 beta packages
stamp 1.0.0b260514, all 3 alpha packages stamp 1.0.0a260514, and
ag-ui remains at 1.0.0rc1 (freshly promoted). Date stamp reflects
2026-05-14 Pacific.

- Released cohort: 1.3.0 -> 1.4.0
- Beta packages (21): 1.0.0b260507 -> 1.0.0b260514
- Alpha packages (3): 1.0.0a260507 -> 1.0.0a260514
- ag-ui: stays at 1.0.0rc1 (dep bound updated only)
- Inter-package dependency lower bounds updated (>=1.3.0 -> >=1.4.0)
- Fix chatkit StructuredInputItem exhaustiveness for openai-chatkit 1.6.4
- Update CHANGELOG compare links
- uv.lock refreshed

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

python/packages/devui/pyproject.toml

@@ -4,7 +4,7 @@ description = "Debug UI for Microsoft Agent Framework with OpenAI-compatible API
 authors = [{ name = "Microsoft", email = "af-support@microsoft.com"}]
 readme = "README.md"
 requires-python = ">=3.10"
-version = "1.0.0b260507"
+version = "1.0.0b260514"
 license-files = ["LICENSE"]
 urls.homepage = "https://github.com/microsoft/agent-framework"
 urls.source = "https://github.com/microsoft/agent-framework/tree/main/python"
@@ -23,7 +23,7 @@ classifiers = [
   "Typing :: Typed",
 ]
  dependencies = [
-     "agent-framework-core>=1.3.0,<2",
+     "agent-framework-core>=1.4.0,<2",
      "openai>=1.99.0,<3",
      "opentelemetry-sdk>=1.39.0,<2",
      "fastapi>=0.115.0,<0.133.1",