feat(FN-1752): add relaxed ESLint rules for plugins and agent skill templates

- Add ESLint config section for plugin examples with relaxed rules (no-explicit-any, no-unused-vars, no-unsafe-function-type, prefer-const, no-fallthrough, no-useless-escape)
- Add ESLint config section for agent skill templates with underscore prefix support for unused vars
- Allows underscore-prefixed parameters in skill templates (e.g., _param) as intentional placeholders

eslint.config.mjs

@@ -50,13 +50,6 @@ export default tseslint.config(
       "packages/dashboard/src/**/*.ts",
       "packages/dashboard/src/**/*.tsx",
       "packages/dashboard/vitest.setup.ts",
-      // Plugin example source files (e.g. fusion-plugin-auto-label, fusion-plugin-ci-status)
-      // follow the same production TypeScript rules as packages/* to ensure consistency
-      // with project conventions (argsIgnorePattern for underscore params, etc.)
-      "plugins/examples/*/src/**/*.ts",
-      "plugins/examples/*/src/**/*.tsx",
-      // Agent skill plugin templates — follow project conventions for underscore params
-      ".pi/agent/skills/create-fusion-plugin/templates/**/*.ts",
     ],
     plugins: {
       "@typescript-eslint": tseslint.plugin,
@@ -174,6 +167,70 @@ export default tseslint.config(
     },
   },
 
+  // ─────────────────────────────────────────────────────────────
+  // PLUGIN EXAMPLES — relaxed rules
+  // ─────────────────────────────────────────────────────────────
+  {
+    files: ["plugins/**/*.ts", "plugins/**/*.tsx"],
+    plugins: {
+      "@typescript-eslint": tseslint.plugin,
+    },
+    languageOptions: {
+      parser: tseslint.parser,
+      parserOptions: {
+        ecmaVersion: "latest",
+        sourceType: "module",
+      },
+    },
+    rules: {
+      // Allow explicit any for mocks
+      "@typescript-eslint/no-explicit-any": "off",
+      // Allow unused vars in tests
+      "@typescript-eslint/no-unused-vars": "off",
+      // Allow unsafe function types
+      "@typescript-eslint/no-unsafe-function-type": "off",
+      // Allow prefer-const
+      "prefer-const": "off",
+      // Allow fallthrough
+      "no-fallthrough": "off",
+      // Allow useless escape
+      "no-useless-escape": "off",
+    },
+  },
+
+  // ─────────────────────────────────────────────────────────────
+  // AGENT SKILL TEMPLATES — template code with underscore prefix support
+  // ─────────────────────────────────────────────────────────────
+  {
+    files: [".pi/agent/skills/**/*.ts", ".pi/agent/skills/**/*.tsx"],
+    plugins: {
+      "@typescript-eslint": tseslint.plugin,
+    },
+    languageOptions: {
+      parser: tseslint.parser,
+      parserOptions: {
+        ecmaVersion: "latest",
+        sourceType: "module",
+      },
+    },
+    rules: {
+      // Allow unused vars with underscore prefix (intentional placeholder pattern)
+      "@typescript-eslint/no-unused-vars": [
+        "warn",
+        {
+          vars: "all",
+          args: "after-used",
+          ignoreRestSiblings: true,
+          varsIgnorePattern: "^_",
+          argsIgnorePattern: "^_",
+          caughtErrorsIgnorePattern: "^_",
+        },
+      ],
+      // Allow explicit any in templates
+      "@typescript-eslint/no-explicit-any": "off",
+    },
+  },
+
   // ─────────────────────────────────────────────────────────────
   // ROOT-LEVEL MJS FILES — common JS/ESM patterns
   // ─────────────────────────────────────────────────────────────