fix: glue --flag=value instead of --flag value, avoiding argv ambiguity

Real bug caught by live CI (not the release-timing gap, which was
separately expected and has since resolved): "--flag value" as two
argv tokens is ambiguous when value itself starts with "-" - e.g.
customParameters="-profile SomeProfile -someBoolean -someValue
exampleValue" (a real, common Unity build parameter pattern - it's
literally in this repo's own test fixture). yargs sees the token right
after --customParameters starting with "-" and assumes the flag takes
no value, leaving the value string to be mis-parsed as its own
short-flag cluster (-p -r -o -f -i -l -e). Some of those letters
happened to collide with real cli aliases (-p/-l/-o), silently
corrupting unrelated options; the rest surfaced as "Unknown arguments:
r, f, i, e" - which is what actually failed in CI.

Verified against the real cli binary locally (bun run src/index.ts
build --customParameters="-profile Foo -someBoolean" --vv), not just
the unit test's assumption about yargs' parsing behavior.

dist/index.js

@@ -80,7 +80,7 @@ function buildCliArgs({ getInput }) {
     if (!targetPlatform) {
         throw new Error('targetPlatform is required.');
     }
-    args.push('--targetPlatform', targetPlatform);
+    args.push(`--targetPlatform=${targetPlatform}`);
     const providerStrategy = getInput('providerStrategy') || 'local';
     if (providerStrategy !== 'local') {
         throw new Error(`Provider strategy "${providerStrategy}" is not supported by this thin wrapper. ` +
@@ -89,8 +89,14 @@ function buildCliArgs({ getInput }) {
     }
     for (const [input, flag] of STRING_FLAGS) {
         const value = getInput(input);
+        // "--flag value" as two argv tokens is ambiguous when value itself
+        // starts with "-" (e.g. customParameters="-profile Foo -someBoolean"):
+        // yargs sees the next token starting with "-" and assumes the flag
+        // takes no value, leaving the value string to be mis-parsed as its own
+        // (partly alias-colliding) short-flag cluster. "--flag=value" glues
+        // them into one token, which is unambiguous.
         if (value)
-            args.push(`--${flag}`, value);
+            args.push(`--${flag}=${value}`);
     }
     for (const [input, flag] of BOOLEAN_FLAGS) {
         const value = getInput(input);