feat: add kotlin commands and skill pack

.cursor/rules/kotlin-security.md

@@ -0,0 +1,58 @@
+---
+description: "Kotlin security extending common rules"
+globs: ["**/*.kt", "**/*.kts", "**/build.gradle.kts"]
+alwaysApply: false
+---
+# Kotlin Security
+
+> This file extends the common security rule with Kotlin-specific content.
+
+## Secret Management
+
+```kotlin
+val apiKey = System.getenv("API_KEY")
+    ?: throw IllegalStateException("API_KEY not configured")
+```
+
+## SQL Injection Prevention
+
+Always use Exposed's parameterized queries:
+
+```kotlin
+// Good: Parameterized via Exposed DSL
+UsersTable.selectAll().where { UsersTable.email eq email }
+
+// Bad: String interpolation in raw SQL
+exec("SELECT * FROM users WHERE email = '$email'")
+```
+
+## Authentication
+
+Use Ktor's Auth plugin with JWT:
+
+```kotlin
+install(Authentication) {
+    jwt("jwt") {
+        verifier(
+            JWT.require(Algorithm.HMAC256(secret))
+                .withAudience(audience)
+                .withIssuer(issuer)
+                .build()
+        )
+        validate { credential ->
+            val payload = credential.payload
+            if (payload.audience.contains(audience) &&
+                payload.issuer == issuer &&
+                payload.subject != null) {
+                JWTPrincipal(payload)
+            } else {
+                null
+            }
+        }
+    }
+}
+```
+
+## Null Safety as Security
+
+Kotlin's type system prevents null-related vulnerabilities -- avoid `!!` to maintain this guarantee.