feat: initialize frontend with React and Vite setup

- Add main application structure with App component
- Implement state management for counter functionality
- Create CSS styles for application layout and components
- Include assets for logos and hero image
- Set up Vite configuration for development environment
- Establish global CSS variables for theming

backend/app/services/orcid_client.py

@@ -0,0 +1,76 @@
+import httpx
+import os
+from typing import Optional
+
+
+class ORCIDClient:
+    """
+    Cliente para interactuar con la Public API de ORCID.
+    Permite:
+    - Obtener token público
+    - Consultar /record
+    - Consultar /works
+    """
+
+    TOKEN_URL = "https://orcid.org/oauth/token"
+    BASE_URL = "https://pub.orcid.org/v3.0"
+
+    def __init__(self):
+        self.client_id = os.getenv("ORCID_CLIENT_ID")
+        self.client_secret = os.getenv("ORCID_CLIENT_SECRET")
+        self._token_cache: Optional[str] = None
+
+    # ---------------------------------------------------------
+    # 1. Obtener token público
+    # ---------------------------------------------------------
+    def get_public_token(self) -> str:
+        """
+        Obtiene un token público de ORCID (scope: /read-public).
+        Se cachea en memoria para evitar pedirlo cada vez.
+        """
+        if self._token_cache:
+            return self._token_cache
+
+        data = {
+            "client_id": self.client_id,
+            "client_secret": self.client_secret,
+            "grant_type": "client_credentials",
+            "scope": "/read-public"
+        }
+
+        with httpx.Client(timeout=20.0) as client:
+            response = client.post(self.TOKEN_URL, data=data)
+            response.raise_for_status()
+            token = response.json()["access_token"]
+            self._token_cache = token
+            return token
+
+    # ---------------------------------------------------------
+    # Headers comunes
+    # ---------------------------------------------------------
+    def _headers(self):
+        token = self.get_public_token()
+        return {
+            "Accept": "application/json",
+            "Authorization": f"Bearer {token}"
+        }
+
+    # ---------------------------------------------------------
+    # 2. Consultar /record
+    # ---------------------------------------------------------
+    def fetch_record(self, orcid_id: str) -> dict:
+        url = f"{self.BASE_URL}/{orcid_id}/record"
+        with httpx.Client(timeout=20.0) as client:
+            response = client.get(url, headers=self._headers())
+            response.raise_for_status()
+            return response.json()
+
+    # ---------------------------------------------------------
+    # 3. Consultar /works
+    # ---------------------------------------------------------
+    def fetch_works(self, orcid_id: str) -> dict:
+        url = f"{self.BASE_URL}/{orcid_id}/works"
+        with httpx.Client(timeout=20.0) as client:
+            response = client.get(url, headers=self._headers())
+            response.raise_for_status()
+            return response.json()