build(android): release signing + mirror/JDK setup; native-feel CSS

- Release signing via android/keystore.properties (git-ignored); build.gradle
  signs release builds when the props file is present, stays unsigned otherwise.
- android/mirror-init.gradle: injects the myket.ir Maven mirror into every
  project's buildscript (dl.google.com is unreachable here) and pins Build-Tools
  to the installed 36.0.0. Build with:
    gradlew assembleRelease bundleRelease -I mirror-init.gradle
  (JAVA_HOME must point at a JDK 21 — Capacitor 8 compiles against Java 21.)
- gitignore keystores, keystore.properties, and /dist artifacts.
- Native-app feel: kill tap-highlight, long-press callout, and stray text
  selection (inputs/messages opt back in); touch-action: manipulation.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

android/app/build.gradle

@@ -1,5 +1,14 @@
 apply plugin: 'com.android.application'
 
+// Release signing is read from android/keystore.properties (git-ignored). When it
+// is absent (e.g. fresh checkout / CI without secrets) the release build stays
+// unsigned instead of failing the configuration.
+def keystorePropsFile = rootProject.file("keystore.properties")
+def keystoreProps = new Properties()
+if (keystorePropsFile.exists()) {
+    keystoreProps.load(new FileInputStream(keystorePropsFile))
+}
+
 android {
     namespace = "com.bargevasat.app"
     compileSdk = rootProject.ext.compileSdkVersion
@@ -16,8 +25,21 @@ android {
             ignoreAssetsPattern = '!.svn:!.git:!.ds_store:!*.scc:.*:!CVS:!thumbs.db:!picasa.ini:!*~'
         }
     }
+    signingConfigs {
+        if (keystorePropsFile.exists()) {
+            release {
+                storeFile file(keystoreProps['storeFile'])
+                storePassword keystoreProps['storePassword']
+                keyAlias keystoreProps['keyAlias']
+                keyPassword keystoreProps['keyPassword']
+            }
+        }
+    }
     buildTypes {
         release {
+            if (keystorePropsFile.exists()) {
+                signingConfig signingConfigs.release
+            }
             minifyEnabled false
             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
         }