minecraft-server: move to the java25 line (4.1.0+up2026.8.2.java25)

Minecraft 26.2 requires Java 25, so the chart's default minecraft.version can
only be raised on a java25 image. appVersion becomes 2026.8.2-java25 - the same
dated upstream release the java21 line ships, so the only variables that change
are the JVM and the Minecraft version.

The chart version stays at 4.1.0: the Java lines are siblings of one chart
generation, not successors, and are told apart by the +up suffix.

The Java boundaries in the values.yaml / NOTES.txt comments are read off
Mojang's version manifest (javaVersion.majorVersion per release), not
estimated: 1.21.11 is the last release asking for Java 21, every release from
26.1 on asks for Java 25.

minecraft-server/Chart.yaml

@@ -6,15 +6,16 @@ icon: https://avatars.githubusercontent.com/u/988985
 type: application
 
 # The Java line of this chart version is chosen through appVersion, which is
-# the image tag: the chart is published once per line (java8 / java17 / java21)
-# and minecraft.version in values.yaml must match the line published here.
+# the image tag: the chart is published once per line (java8 / java17 / java21 /
+# java25) and minecraft.version in values.yaml must match the line published
+# here.
 # Since chart 2.0.0 the tag is a DATED upstream release ("<release>-java<N>")
 # instead of the rolling line tag ("java<N>"): the rolling tags are rebuilt
 # continuously, so a pod restart could pull a different image than the last one
 # without anything being recorded anywhere. The dated tags are immutable, so the
 # image is now pinned by the chart version like every other chart in this repo.
-version: 4.1.0+up2026.8.2.java21
-appVersion: "2026.8.2-java21"
+version: 4.1.0+up2026.8.2.java25
+appVersion: "2026.8.2-java25"
 
 maintainers:
   - name: jklein

minecraft-server/templates/NOTES.txt

@@ -81,11 +81,13 @@ THIS CHART IS PUBLISHED ONCE PER JAVA LINE — THIS IS {{ $line | default "an un
   ({{ .Chart.AppVersion }}), not from a value. This build runs
   minecraft.version {{ .Values.minecraft.version }}.
 
-  Java 8 runs Minecraft up to 1.16.5, 1.18-1.20.4 need Java 17 and 1.20.5+ need
-  Java 21. Nothing in this chart checks that minecraft.version fits the line:
-  a mismatch renders and installs without a word, and only the container fails
-  afterwards — CrashLoopBackOff once the startup budget{{ if $budget }} ({{ $budget }}){{ end }} is spent, with
-  the reason in the log and nowhere else:
+  Java 8 runs Minecraft up to 1.16.5, 1.18-1.20.4 need Java 17, 1.20.5-1.21.11
+  need Java 21 and 26.1 and later need Java 25 (read off Mojang's version
+  manifest, javaVersion.majorVersion per release). Nothing in this chart checks
+  that minecraft.version fits the line: a mismatch renders and installs without
+  a word, and only the container fails afterwards — CrashLoopBackOff once the
+  startup budget{{ if $budget }} ({{ $budget }}){{ end }} is spent, with the reason in the log and
+  nowhere else:
 
     kubectl -n {{ .Release.Namespace }} logs {{ $pod }}
 

minecraft-server/values.yaml

@@ -225,9 +225,13 @@ minecraft:
   # drift to a new release on every restart.
   # This value must match the Java line of the chart version: the image tag
   # comes from .Chart.AppVersion, so the JVM is fixed per published chart
-  # version. Java 8 runs Minecraft up to 1.16.5, 1.18-1.20.4 need Java 17 and
-  # 1.20.5+ need Java 21. This chart publishes appVersion "2026.8.2-java21".
-  version: "1.21.1"
+  # version. Java 8 runs Minecraft up to 1.16.5, 1.18-1.20.4 need Java 17,
+  # 1.20.5-1.21.11 need Java 21 and 26.1 and later need Java 25. The two upper
+  # boundaries are read off Mojang's version manifest (piston-meta, field
+  # javaVersion.majorVersion per release), not estimated: 1.21.11 (2025-12-09)
+  # is the last release asking for 21, and every release from 26.1 (2026-03-24)
+  # on asks for 25. This chart publishes appVersion "2026.8.2-java25".
+  version: "26.2"
 
 # curseforge, ftb and curseforgeServerpack are mutually exclusive - enabling
 # more than one is rejected by the chart (before 1.0.0 it silently rendered a