feat: refactor skills API and database schema

- Replaced file-based skill category loading with API calls in the GET and POST methods of the skills route.
- Added new `SkillsService` for handling skill category operations.
- Updated SQL initialization script to create `skill_categories`, `skills`, and `skill_links` tables with appropriate relationships.
- Enhanced `ApiClient` with methods for loading skill categories and creating new skills, improving API interaction.
- Introduced error handling for skill category creation and loading processes.

scripts/migrate-skills.ts

@@ -0,0 +1,54 @@
+import { SkillsService } from "../services/skills-service";
+import { loadSkillCategoriesFromFiles } from "../lib/skill-file-loader";
+
+async function migrateSkillsToDatabase() {
+  console.log("🚀 Starting skills migration...");
+
+  try {
+    // Load all skill categories from JSON files
+    const skillCategories = loadSkillCategoriesFromFiles();
+
+    console.log(`📊 Found ${skillCategories.length} categories`);
+
+    const totalSkills = skillCategories.reduce(
+      (sum, cat) => sum + cat.skills.length,
+      0
+    );
+    console.log(`🎯 Total skills to migrate: ${totalSkills}`);
+
+    // Bulk insert into database
+    await SkillsService.bulkInsertSkillsFromJSON(skillCategories);
+
+    console.log("✅ Skills migration completed successfully!");
+
+    // Verify the migration
+    const categoriesFromDb = await SkillsService.getSkillCategories();
+    console.log(
+      `✨ Verification: ${categoriesFromDb.length} categories in database`
+    );
+
+    const totalSkillsInDb = categoriesFromDb.reduce(
+      (sum, cat) => sum + cat.skills.length,
+      0
+    );
+    console.log(`✨ Verification: ${totalSkillsInDb} skills in database`);
+  } catch (error) {
+    console.error("❌ Migration failed:", error);
+    process.exit(1);
+  }
+}
+
+// Run if called directly
+if (require.main === module) {
+  migrateSkillsToDatabase()
+    .then(() => {
+      console.log("🎉 Migration script completed");
+      process.exit(0);
+    })
+    .catch((error) => {
+      console.error("💥 Migration script failed:", error);
+      process.exit(1);
+    });
+}
+
+export { migrateSkillsToDatabase };