feat(jetbrains): add detekt for cyclomatic complexity and file size limits

Adds detekt static analysis to enforce complexity and file size caps
in kilo-jetbrains, mirroring the ESLint complexity/max-lines rules
used by the VS Code extension.

packages/kilo-jetbrains/build.gradle.kts

@@ -9,6 +9,7 @@ plugins {
     application
     id("java")
     alias(libs.plugins.intellij.platform)
+    alias(libs.plugins.detekt)
 
     alias(libs.plugins.kotlin) apply false
     alias(libs.plugins.kotlin.serialization) apply false
@@ -17,6 +18,19 @@ plugins {
 
 subprojects {
     apply(plugin = "org.jetbrains.intellij.platform.module")
+    apply(plugin = "io.gitlab.arturbosch.detekt")
+
+    detekt {
+        config.setFrom(rootProject.file("detekt.yml"))
+        buildUponDefaultConfig = true
+        source.setFrom("src/main/kotlin")
+    }
+}
+
+detekt {
+    config.setFrom(file("detekt.yml"))
+    buildUponDefaultConfig = true
+    source.setFrom("src/main/kotlin")
 }
 
 allprojects {

packages/kilo-jetbrains/detekt.yml

@@ -0,0 +1,30 @@
+# Detekt configuration for kilo-jetbrains.
+#
+# Enforces file size and cyclomatic complexity limits — the Kotlin
+# equivalent of the ESLint complexity/max-lines rules used by the
+# VS Code extension (packages/kilo-vscode/eslint.config.mjs).
+#
+# New code must stay within the default limits. Do not raise these
+# caps; refactor instead.
+
+complexity:
+  CyclomaticComplexMethod:
+    active: true
+    threshold: 15
+  LongMethod:
+    active: true
+    threshold: 60
+  LargeClass:
+    active: true
+    threshold: 600
+  TooManyFunctions:
+    active: true
+    threshold: 15
+  ComplexCondition:
+    active: true
+    threshold: 4
+  LongParameterList:
+    active: false
+  NestedBlockDepth:
+    active: true
+    threshold: 4

packages/kilo-jetbrains/gradle/libs.versions.toml

@@ -7,6 +7,7 @@ kotlin-serialization-plugin = "2.1.20"
 kotlin-serialization = "1.8.1"
 okhttp = "4.12.0"
 openapi-generator = "7.21.0"
+detekt = "1.23.8"
 
 [libraries]
 okhttp = { module = "com.squareup.okhttp3:okhttp", version.ref = "okhttp" }
@@ -16,6 +17,7 @@ kotlinx-serialization-json = { module = "org.jetbrains.kotlinx:kotlinx-serializa
 kotlinx-coroutines-test = { module = "org.jetbrains.kotlinx:kotlinx-coroutines-test", version = "1.10.2" }
 
 [plugins]
+detekt = { id = "io.gitlab.arturbosch.detekt", version.ref = "detekt" }
 intellij-platform = { id = "org.jetbrains.intellij.platform", version.ref = "intellij-gradle-plugin" }
 rpc = { id = "rpc", version.ref = "intellij-rpc-plugin" }
 kotlin = { id = "org.jetbrains.kotlin.jvm", version.ref = "kotlin-jvm-plugin" }