Fix JDK resolution cache platform identity (#1210)

* Fix JDK resolution cache platform identity

Include the effective Linux libc platform in JDK resolution cache keys so Alpine/musl and glibc runners cannot restore each other's release metadata. Bump the cache namespace and share Alpine detection with affected distributors.\n\nCo-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>\nCopilot-Session: 4f95577c-567c-47a8-92f2-b4dced527866

* Update generated action bundles

Regenerate setup and cleanup distributions for the platform-aware JDK resolution cache.\n\nCo-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>\nCopilot-Session: 4f95577c-567c-47a8-92f2-b4dced527866

* Cover the platform-identity fallback and Alpine short-circuit

getJavaPlatformIdentity's `?? platform` fallback and the alias path for
platforms other than linux/darwin/win32 had no coverage, and isAlpineLinux
had no direct test at all.

Verified by mutation: replacing the fallback with a constant, and dropping
the `platform === 'linux'` short-circuit from isAlpineLinux, both left the
existing suite fully green. The added cases fail on each.

The short-circuit case matters beyond coverage bookkeeping: it is what keeps
the /etc/alpine-release probe from running on non-Linux runners, so a stray
file can never make Windows or macOS resolve as musl.

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 74248bb0-72af-41d8-b85d-b0f5836e68db

* Carry the platform identity into the floating resolution request

Merging main brought in #1219, which added getFloatingResolutionRequest
as a second construction site for JdkResolutionRequest. It predates the
required `platform` field, so the merged tree did not compile.

The floating request already carries `source`, which pins the artifact
bytes, so this changes no lookup behaviour on its own -- it keeps the two
request builders consistent and the tree building.

Also refreshes dist/, which the textual merge left stale.

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 74248bb0-72af-41d8-b85d-b0f5836e68db

---------

Co-authored-by: Bruno Borges <brborges@microsoft.com>
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 74248bb0-72af-41d8-b85d-b0f5836e68db

__tests__/java-platform-contract.test.ts

@@ -1,6 +1,8 @@
 import fs from 'fs';
 import path from 'path';
 import {
+  getJavaPlatformIdentity,
+  isAlpineLinux,
   JAVA_PLATFORM_CAPABILITIES,
   normalizeArchitecture,
   validateJavaPlatform
@@ -28,6 +30,38 @@ describe('Java platform capabilities', () => {
     expect(normalizeArchitecture(input)).toBe(expected);
   });
 
+  it.each([
+    ['linux', false, 'linux-glibc'],
+    ['linux', true, 'linux-musl'],
+    ['darwin', false, 'macos'],
+    ['win32', false, 'windows'],
+    // Exercises the normalizePlatform alias path and the `?? platform`
+    // fallback for a platform that has no Java alias.
+    ['sunos', false, 'solaris'],
+    ['aix', false, 'aix']
+  ] as const)(
+    'identifies %s with Alpine release %s as %s',
+    (platform, alpineReleaseExists, expected) => {
+      expect(getJavaPlatformIdentity(platform, alpineReleaseExists)).toBe(
+        expected
+      );
+    }
+  );
+
+  // The platform check has to short-circuit before the filesystem probe, so a
+  // stray /etc/alpine-release can never make a non-Linux runner look like musl.
+  it.each([
+    ['linux', true, true],
+    ['linux', false, false],
+    ['darwin', true, false],
+    ['win32', true, false]
+  ] as const)(
+    'treats %s with Alpine release %s as Alpine: %s',
+    (platform, alpineReleaseExists, expected) => {
+      expect(isAlpineLinux(platform, alpineReleaseExists)).toBe(expected);
+    }
+  );
+
   it('uses the normalized architecture for validation', () => {
     expect(validateJavaPlatform('microsoft', 'linux', 'arm64', '25')).toBe(
       'aarch64'