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.

app/api/skills/route.ts

@@ -1,35 +1,10 @@
 import { NextResponse } from "next/server";
-import fs from "fs";
-import path from "path";
+import { SkillsService } from "@/services";
 import { SkillCategory } from "@/lib/types";
 
 export async function GET() {
   try {
-    const dataDir = path.join(process.cwd(), "data", "skills");
-
-    const categories = [
-      "frontend",
-      "backend",
-      "devops",
-      "mobile",
-      "data",
-      "cloud",
-      "security",
-      "design",
-    ];
-
-    const skillCategories: SkillCategory[] = [];
-
-    for (const category of categories) {
-      const filePath = path.join(dataDir, `${category}.json`);
-
-      if (fs.existsSync(filePath)) {
-        const fileContent = fs.readFileSync(filePath, "utf-8");
-        const data = JSON.parse(fileContent);
-        skillCategories.push(data);
-      }
-    }
-
+    const skillCategories = await SkillsService.getSkillCategories();
     return NextResponse.json(skillCategories);
   } catch (error) {
     console.error("Error loading skills:", error);
@@ -39,3 +14,27 @@ export async function GET() {
     );
   }
 }
+
+export async function POST(request: Request) {
+  try {
+    const categoryData: { id: string; name: string; icon: string } =
+      await request.json();
+
+    // Validate required fields
+    if (!categoryData.id || !categoryData.name || !categoryData.icon) {
+      return NextResponse.json(
+        { error: "Missing required fields: id, name, icon" },
+        { status: 400 }
+      );
+    }
+
+    await SkillsService.createSkillCategory(categoryData);
+    return NextResponse.json({ success: true }, { status: 201 });
+  } catch (error) {
+    console.error("Error creating skill category:", error);
+    return NextResponse.json(
+      { error: "Failed to create skill category" },
+      { status: 500 }
+    );
+  }
+}