Adopt Xcode recommended settings and fix resulting build errors

Applied Xcode's "Update to recommended settings" (new warning flags,
LastUpgradeCheck 2650, scheme bumps, Info.plist tidy-up), then fixed the
build failures those stricter checks surfaced:

- Disable ENABLE_MODULE_VERIFIER and CLANG_WARN_QUOTED_INCLUDE_IN_FRAMEWORK_HEADER:
  the library intentionally uses quoted includes so the flat include/
  symlink directory resolves them for SPM; the module verifier rejects
  that.
- Add (void) to the GCDWebServerInitializeFunctions and
  _ExecuteMainThreadRunLoopSources definitions (CLANG_WARN_STRICT_PROTOTYPES
  + -Werror).
- Cast both branches of the status-code ternary in
  GCDWebServerConnection to NSInteger (-Wenum-compare-conditional mixed
  two enum types).

Verified: Run-Tests.sh, swift build, and the Xcode framework build all pass.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Frameworks/Info.plist

@@ -7,16 +7,16 @@
 	<key>CFBundleExecutable</key>
 	<string>$(EXECUTABLE_NAME)</string>
 	<key>CFBundleIdentifier</key>
-	<string>${PRODUCT_BUNDLE_IDENTIFIER}</string>
+	<string>$(PRODUCT_BUNDLE_IDENTIFIER)</string>
 	<key>CFBundleInfoDictionaryVersion</key>
 	<string>6.0</string>
 	<key>CFBundleName</key>
 	<string>$(PRODUCT_NAME)</string>
 	<key>CFBundlePackageType</key>
 	<string>FMWK</string>
-	<key>CFBundleVersion</key>
-	<string>${BUNDLE_VERSION_STRING}</string>
 	<key>CFBundleShortVersionString</key>
 	<string>${BUNDLE_VERSION_STRING}</string>
+	<key>CFBundleVersion</key>
+	<string>${BUNDLE_VERSION_STRING}</string>
 </dict>
 </plist>