fix: resolve WASM/UI and Windows CI failures

- ui: JoinSplitKey initialValues now uses DEFAULT_SHARE_COUNT (3) instead
  of a hardcoded array of 2 entries, making the initial render consistent
  with the constant and fixing the 'join-share-id-2' unit test failure

- windows: set RUST_MIN_STACK=8388608 in cargo_test.ps1 to give test
  threads an 8 MB stack (matching Linux/macOS defaults); prevents the
  STATUS_STACK_OVERFLOW crash in integration_tests_use_ids_no_tags on
  debug builds where async state machines have larger stack frames

Author: Manuthor

.mise/scripts/windows/cargo_test.ps1

@@ -5,6 +5,9 @@ $PSNativeCommandUseErrorActionPreference = $true # might be true by default
 function TestProject
 {
     $env:RUST_LOG = "cosmian_kms_cli=error,cosmian_kms_server=error,cosmian_kmip=error,test_kms_server=error"
+    # Windows default thread stack is 1 MB; large async test functions overflow it in
+    # debug builds. 8 MB matches the Linux/macOS default (RUST_MIN_STACK is bytes).
+    $env:RUST_MIN_STACK = "8388608"
     # Add target
     rustup target add x86_64-pc-windows-msvc
 

ui/src/actions/Keys/JoinSplitKey.tsx

@@ -102,7 +102,7 @@ const JoinSplitKeyForm: React.FC = () => {
                 initialValues={{
                     method: "XOR",
                     objectType: "SymmetricKey",
-                    shareIds: [{ value: "" }, { value: "" }],
+                    shareIds: Array.from({ length: DEFAULT_SHARE_COUNT }, () => ({ value: "" })),
                 }}
             >
                 <Space direction="vertical" size="middle" style={{ display: "flex" }}>