Build: make Android build work behind restrictive proxies

- settings.gradle.kts: comment out the foojay-resolver-convention plugin.
  It tries to auto-download JDK toolchains from api.foojay.io, which fails
  with 503 behind restrictive proxies. Re-enable at home if you want
  auto-provisioning.
- app/build.gradle.kts: comment out jvmToolchain(17) for the same reason
  (triggers toolchain resolution -> foojay download). The build JDK 21
  plus compileOptions(source/target 17) achieves the same result locally.
- gradle-wrapper.properties: bump to gradle-9.6.1-all (matches the
  manually provided distribution).
- .gitignore: ignore .ssl-work/ (local corporate-CA truststore).

android/app/build.gradle.kts

@@ -58,7 +58,10 @@ room {
 }
 
 kotlin {
-  jvmToolchain(17)
+  // Use the JDK running Gradle instead of resolving a toolchain (avoids
+  // foojay-resolver downloads behind restrictive proxies). compileOptions
+  // above pins source/target to 17.
+  // jvmToolchain(17)
 }
 
 dependencies {