feat(lint): add icon color variable policies

Sources/ExFigCLI/ExFig.docc/Usage.md

@@ -298,6 +298,9 @@ Validate your Figma file structure against your PKL config before exporting:
 # Lint with default rules
 exfig lint -i exfig.pkl
 
+# Add lint-only policies from a separate config
+exfig lint -i exfig.pkl --lint-config lint.pkl
+
 # Only check specific rules
 exfig lint -i exfig.pkl --rules naming-convention,deleted-variables
 
@@ -307,17 +310,18 @@ exfig lint -i exfig.pkl --format json --severity error
 
 ### Available Rules
 
-| Rule                       | Severity | Description                                            |
-| -------------------------- | -------- | ------------------------------------------------------ |
-| `frame-page-match`         | error    | Frame/page names in config exist in Figma file         |
-| `naming-convention`        | error    | Component names match `nameValidateRegexp` patterns    |
-| `component-not-frame`      | error    | Configured frames contain published components         |
-| `duplicate-component-names`| error    | No duplicate component names in configured frames      |
-| `deleted-variables`        | warning  | No `deletedButReferenced` variables in collections     |
-| `alias-chain-integrity`    | warning  | Variable alias chains resolve without broken refs      |
-| `dark-mode-variables`      | error    | With `variablesDarkMode`, fills bound to Variables     |
-| `dark-mode-suffix`         | warning  | With `suffixDarkMode`, light components have dark pair |
-| `path-data-length`         | error    | Icon SVG pathData within 32,767-byte AAPT limit        |
+| Rule                        | Severity | Description                                            |
+| --------------------------- | -------- | ------------------------------------------------------ |
+| `frame-page-match`          | error    | Frame/page names in config exist in Figma file         |
+| `naming-convention`         | error    | Component names match `nameValidateRegexp` patterns    |
+| `component-not-frame`       | error    | Configured frames contain published components         |
+| `duplicate-component-names` | error    | No duplicate component names in configured frames      |
+| `deleted-variables`         | warning  | No `deletedButReferenced` variables in collections     |
+| `alias-chain-integrity`     | warning  | Variable alias chains resolve without broken refs      |
+| `dark-mode-variables`       | error    | With `variablesDarkMode`, fills bound to Variables     |
+| `dark-mode-suffix`          | warning  | With `suffixDarkMode`, light components have dark pair |
+| `path-data-length`          | error    | Icon SVG pathData within 32,767-byte AAPT limit        |
+| `icon-color-variables`      | error    | Icon paints use configured Figma Variables             |
 
 ## Help and Version
 

Sources/ExFigCLI/Lint/LintConfigLoader.swift

@@ -0,0 +1,29 @@
+import ExFigConfig
+import Foundation
+
+/// Loads optional lint-only overlay configuration for `exfig lint`.
+enum LintConfigLoader {
+    static let defaultFileName = "lint.pkl"
+
+    static func resolvePath(explicitPath: String?, mainConfigPath: String?) -> URL? {
+        if let explicitPath, !explicitPath.isEmpty {
+            return URL(fileURLWithPath: explicitPath)
+        }
+
+        let mainPath = mainConfigPath ?? ExFigOptions.defaultConfigFilename
+        let mainURL = URL(fileURLWithPath: mainPath)
+        let lintURL = mainURL.deletingLastPathComponent().appendingPathComponent(defaultFileName)
+
+        guard FileManager.default.fileExists(atPath: lintURL.path) else {
+            return nil
+        }
+        return lintURL
+    }
+
+    static func load(explicitPath: String?, mainConfigPath: String?) async throws -> ExFigConfig.Lint.ModuleImpl? {
+        guard let path = resolvePath(explicitPath: explicitPath, mainConfigPath: mainConfigPath) else {
+            return nil
+        }
+        return try await PKLEvaluator.evaluateLintConfig(configPath: path)
+    }
+}

Sources/ExFigCLI/Lint/LintEngine.swift

@@ -63,5 +63,6 @@ extension LintEngine {
         DarkModeSuffixRule(),
         PathDataLengthRule(),
         InvalidRTLVariantValueRule(),
+        IconColorVariablesLintRule(),
     ])
 }

Sources/ExFigCLI/Lint/LintTypes.swift

@@ -64,6 +64,8 @@ actor LintDataCache {
 struct LintContext {
     /// The resolved PKL configuration.
     let config: ExFig.ModuleImpl
+    /// Optional lint-only overlay configuration.
+    let lintConfig: ExFigConfig.Lint.ModuleImpl?
     /// Figma API client.
     let client: any FigmaAPI.Client
     /// Shared cache for Figma API responses across rules.