chore(docs): write changelogs for leeway token fix

CHANGELOG.md

@@ -1,5 +1,8 @@
 ## Release (2026-MM-DD)
 
+- `core`:
+  - [v0.3.1](core/CHANGELOG.md#v031)
+    - **Fix:** Refresh access tokens five minutes before expiration instead of after, and wait for in-progress refreshes before authorizing requests
 - `alb`:
   - [v0.13.0](services/alb/CHANGELOG.md#v0130)
     - **Feature:** Add `ip_block_list_name` field to `LoadbalancerOptionAccessControl` model

core/CHANGELOG.md

@@ -1,3 +1,6 @@
+## v0.3.1
+- **Fix:** Refresh access tokens five minutes before expiration instead of after, and wait for in-progress refreshes before authorizing requests
+
 ## v0.3.0
 - **Chore:** Bump minimum Python version to 3.10
 - **Chore:** Update dependencies

core/pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "stackit-core"
-version = "v0.3.0"
+version = "v0.3.1"
 description = "Core functionality for the STACKIT SDK for Python"
 authors = [{ name = "STACKIT Developer Tools", email = "developer-tools@stackit.cloud" }]
 requires-python = ">=3.10,<4.0"