Inline CI setup steps; remove broken composite cargo cache action.

Co-authored-by: Cursor <cursoragent@cursor.com>

.github/actions/cache-cargo-windows/action.yml

@@ -1,16 +0,0 @@
-name: Cache Cargo (windows-setup)
-description: Cache registry, git sources, and target/ for the Windows installer Rust workspace
-
-runs:
-  using: composite
-  steps:
-    - name: Cache Cargo
-      uses: actions/cache@v4
-      with:
-        path: |
-          ~/.cargo/registry
-          ~/.cargo/git
-          app/desktop/windows-setup/target
-        key: cargo-windows-${{ runner.os }}-${{ github.sha }}
-        restore-keys: |
-          cargo-windows-${{ runner.os }}-

.github/actions/setup-java-gradle/action.yml

@@ -3,7 +3,7 @@ description: Temurin JDK 17 + Gradle wrapper with dependency and build cache
 
 inputs:
   java-architecture:
-    description: Optional JDK architecture (x64, arm64, …)
+    description: Optional JDK architecture (x64). Omit for host default.
     required: false
     default: ""
 
@@ -11,16 +11,10 @@ runs:
   using: composite
   steps:
     - uses: actions/setup-java@v4
-      if: ${{ inputs.java-architecture != '' && inputs.java-architecture != 'none' }}
       with:
         distribution: temurin
         java-version: "17"
         architecture: ${{ inputs.java-architecture }}
-    - uses: actions/setup-java@v4
-      if: ${{ inputs.java-architecture == '' || inputs.java-architecture == 'none' }}
-      with:
-        distribution: temurin
-        java-version: "17"
 
     - uses: gradle/actions/setup-gradle@v4
       with: