Update enterprise-v2.8.md and release-downloads.md for v2.8.15 (#591)

* Update release-downloads.md for v2.8.15

* Update enterprise-v2.8.md

Author: kuiliu88

docs/enterprise-v2.8.md

@@ -32,6 +32,27 @@ Key highlights of this release:
 ## Releases
 We recommend using stable releases for production deployment. Engineering builds are available for testing and evaluation purposes.
 
+### 2.8.15 (Public GA) {#2_8_15}
+Released on 03-17-2026. Installation options:
+* For Linux or Mac users: `curl https://install.timeplus.com/2.8 | sh` [Downloads](/release-downloads#2_8_15)
+* For Kubernetes users: helm install timeplus/timeplus-enterprise --version v7.0.37 ..
+* For Docker users (not recommended for production): `docker run -p 8000:8000 docker.timeplus.com/timeplus/timeplus-enterprise:2.8.15`
+
+Component versions:
+* timeplusd 2.8.41
+* timeplus_web 2.8.18
+* timeplus_appserver 2.8.13
+* timeplus_connector 2.8.1
+* timeplus cli 2.8.0
+  
+#### Changelog {#changelog_2_8_15}
+Compared to the [2.8.14](#2_8_14) release:
+* timeplusd 2.8.39 -> 2.8.41
+  * Bugfixes  
+    *   Upgraded Pulsar client to v4.0.1.
+    *   Fixed issue which DELETE is skipped on mutable stream in rare condition.
+    *   Fixed bootstrap race condition where timeplusd could restart in rare condition.
+
 ### 2.8.14 (Public GA) {#2_8_14}
 Released on 03-06-2026. Installation options:
 * For Linux or Mac users: `curl https://install.timeplus.com/2.8 | sh` [Downloads](/release-downloads#2_8_14)

docs/release-downloads.md

@@ -34,6 +34,12 @@ Released on 09-25-2025 ([Change logs](/enterprise-v3.0#3_0_1-preview_2)).
 
 ## 2.8 {#2_8}
 
+### v2.8.15 {#2_8_15}
+Released on 03-17-2026 ([Change logs](/enterprise-v2.8#2_8_15)).
+
+* Bare metal installation: [Linux x86_64](https://d.timeplus.com/timeplus-enterprise-v2.8.15-linux-amd64.tar.gz) | [Linux ARM64](https://d.timeplus.com/timeplus-enterprise-v2.8.15-linux-arm64.tar.gz) | [macOS x86_64](https://d.timeplus.com/timeplus-enterprise-v2.8.15-darwin-amd64.tar.gz) | [macOS ARM64](https://d.timeplus.com/timeplus-enterprise-v2.8.15-darwin-arm64.tar.gz)
+* All-in-one Docker image (not recommended for production): `docker run -p 8000:8000 docker.timeplus.com/timeplus/timeplus-enterprise:2.8.15`
+
 ### v2.8.14 {#2_8_14}
 Released on 03-06-2026 ([Change logs](/enterprise-v2.8#2_8_14)).