website/docs: update release notes for 2026.5.6 (#24293)

* website/docs: update release notes for 2026.5.6

* lint

locale/en/dictionaries/software-terms.txt

@@ -142,6 +142,7 @@ recws
 retag
 rnds
 rsa
+runit
 RSTR
 sbdocs
 schedulable

website/docs/releases/2026/v2026.5.md

@@ -593,6 +593,25 @@ This release has been skipped.
 - web: fix table refresh button not refreshing table data (cherry-pick #23780 to version-2026.5) (#23878)
 - web/flows: fix race condition in continuous login and support source stages in authentication flows (cherry-pick #23049 to version-2026.5) (#23558)
 
+## Fixed in 2026.5.6
+
+- core: Form friendly error on uniqueness constraint. (cherry-pick #23864 to version-2026.5) (#23881)
+- endpoints/connectors/agent: fix auth schema for device endpoints (cherry-pick #24164 to version-2026.5) (#24167)
+- enterprise/endpoints/connectors/fleet: pass populate_policies (cherry-pick #24108 to version-2026.5) (#24112)
+- internal/config: make storage file paths overwritable via env vars (cherry-pick #24177 to version-2026.5) (#24220)
+- lifecycle/container: drop curl and runit (cherry-pick #24008 to version-2026.5) (#24114)
+- packages/django-dramatiq-postgres/broker: use positive state filter for pending messages (cherry-pick #24074 to version-2026.5) (#24166)
+- policies: filter policy engine (cherry-pick #24025 to version-2026.5) (#24168)
+- providers/scim: exclude read-only id from group PATCH payload and fix null-members add check (cherry-pick #23950 to version-2026.5) (#24227)
+- providers/scim: fix enum warning when de-serializing (cherry-pick #23553 to version-2026.5) (#24231)
+- providers/scim: fix non-schema compliant group member removal (cherry-pick #23800 to version-2026.5) (#24229)
+- root: fix make gen-changelog (cherry-pick #24122 to version-2026.5) (#24260)
+- root: fix make gen-diff command (cherry-pick #22548 to version-2026.5) (#24121)
+- root: in-process per-IP rate throttle (#23015) (#24217)
+- stages/captcha: fix hcaptcha height (#20901) (#24216)
+- web/admin: fix app view failing when no events permissions (cherry-pick #24131 to version-2026.5) (#24252)
+- web/flow: revert locale-driven flow re-request from FlowExecutor (cherry-pick #24050 to version-2026.5) (#24068)
+
 ## API Changes
 
 ### authentik (v 2026.5.0)
@@ -4985,3 +5004,25 @@ Changed response : **200 OK**
 ---
 
 API changes broke backward compatibility
+
+### authentik (v 2026.5.6)
+
+---
+
+#### What's Changed
+
+---
+
+##### `POST` /endpoints/agents/connectors/auth_fed/
+
+##### `POST` /endpoints/agents/connectors/enroll/
+
+##### `GET` /endpoints/agents/connectors/agent_config/
+
+##### `POST` /endpoints/agents/connectors/check_in/
+
+#### Result
+
+---
+
+API changes are backward compatible