provide Ditto 3.8.12 release notes

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: thjaeckle

documentation/src/main/resources/_data/sidebars/ditto_sidebar.yml

@@ -23,6 +23,9 @@ entries:
       - title: Release Notes
         output: web
         folderitems:
+          - title: 3.8.12
+            url: /release_notes_3812.html
+            output: web
           - title: 3.8.11
             url: /release_notes_3811.html
             output: web

documentation/src/main/resources/pages/ditto/release_notes_3812.md

@@ -0,0 +1,49 @@
+---
+title: Release notes 3.8.12
+tags: [release_notes]
+published: true
+keywords: release notes, announcements, changelog
+summary: "Version 3.8.12 of Eclipse Ditto, released on 11.02.2026"
+permalink: release_notes_3812.html
+---
+
+This is a bugfix release, no new features since [3.8.11](release_notes_3811.html) were added.
+
+## Changelog
+
+Compared to the latest release [3.8.11](release_notes_3811.html), the following changes and bugfixes were added.
+
+### Bugfixes
+
+This is a complete list of the
+[merged pull requests](https://github.com/eclipse-ditto/ditto/pulls?q=is%3Apr+milestone%3A3.8.12).
+
+#### Fix background sync always detecting policy inconsistency for Things with policy imports
+
+PR [#2317](https://github.com/eclipse-ditto/ditto/pull/2317) fixes an issue where background sync always detected a
+policy inconsistency for Things whose Policies have imports. The MongoDB projection in `sudoStreamMetadata()` was
+missing the referenced policies field, causing the indexed metadata to always have an empty set of referenced policies.
+This triggered continuous unnecessary search index updates.
+
+#### Fix aggregate metrics using wrong scrapeInterval and showing 0ms duration
+
+PR [#2334](https://github.com/eclipse-ditto/ditto/pull/2334) fixes two bugs in operator aggregate metrics:
+* `OperatorAggregateMetricsProviderActor` used the maximum configured `scrapeInterval` for all metric timers instead of
+  each metric's own interval. Now each metric's individual `scrapeInterval` is respected, falling back to the global
+  default.
+* `AggregateThingsMetricsActor` measured aggregation duration at stream materialization time instead of at stream
+  completion time, causing the logged duration to always be ~0ms.
+
+#### Fix Policy activation failure when other expired subjects exist
+
+PR [#2335](https://github.com/eclipse-ditto/ditto/pull/2335) fixes a bug where `activateTokenIntegration` requests
+failed when the Policy contained other subjects that were already expired but still within their grace period before
+deletion. Now only the requested subject is checked for being expired, instead of checking the entire Policy.
+
+### Helm Chart
+
+#### Expose Pekko HTTP host pool max connection lifetime via Helm values
+
+PR [#2336](https://github.com/eclipse-ditto/ditto/pull/2336) adds `connectivity.config.connections.httpPush.maxConnectionLifetime`
+to Helm values (default: `"Inf"`) and wires it to the `PEKKO_HTTP_HOSTPOOL_MAX_CONNECTION_LIFETIME` environment variable
+in the connectivity deployment template.