chore: clean up generated files and update gitignore

- remove api-docs.json from version control
- add src-tauri/gen/ to gitignore

scripts/patch-android-signing.sh

@@ -0,0 +1,28 @@
+#!/usr/bin/env bash
+# Patch the generated Android build.gradle.kts with signing configuration.
+# Run this after `tauri android init` if the signing config is missing.
+
+set -euo pipefail
+
+BUILD_FILE="src-tauri/gen/android/app/build.gradle.kts"
+SIGNING_FILE="src-tauri/android-signing.gradle.kts"
+
+if [ ! -f "$BUILD_FILE" ]; then
+    echo "Error: $BUILD_FILE not found. Run 'tauri android init' first."
+    exit 1
+fi
+
+# Check if signing is already configured
+if grep -q "keystoreProperties" "$BUILD_FILE" 2>/dev/null; then
+    echo "Signing already configured in $BUILD_FILE"
+    exit 0
+fi
+
+# Insert signing config block: find `signingConfigs` or add it before `buildTypes`,
+# then add `signingConfig` to the release buildType.
+# Strategy: replace the entire android block content using the external apply approach.
+
+# Inject the apply-line at end of file (before the tauri.build.gradle.kts apply)
+sed -i 's|apply(from = "tauri.build.gradle.kts")|apply(from = "../../../android-signing.gradle.kts")\napply(from = "tauri.build.gradle.kts")|' "$BUILD_FILE"
+
+echo "Signing config patched into $BUILD_FILE"