fix: resolve all linting issues in command files

Refactored createIssue, createTask, and onboardMentee commands to
extract helper functions, fix JSDoc descriptions, correct type
handling, and satisfy all ESLint rules. Also fixed object-shorthand
mixing in index.ts and the naming convention in anthropic.ts.

src/utils/anthropic.ts

@@ -4,6 +4,7 @@
  * @author Naomi Carrigan
  */
 
+// eslint-disable-next-line @typescript-eslint/naming-convention -- SDK default export uses PascalCase.
 import Anthropic from "@anthropic-ai/sdk";
 
 export const anthropic = new Anthropic({