adding add forms

src/components/CandidacyForm.jsx

+import React, { useState, useEffect } from "react";
+
+const CandidacyForm = () => {
+  const [students, setStudents] = useState([]);
+  const [stages, setStages] = useState([]);
+  const [supervisors, setSupervisors] = useState([]); // Load supervisors
+
+  const [formData, setFormData] = useState({
+    studentId: "",
+    stageId: "",
+    univSupervisorId: "", // Add supervisor field
+  });
+
+  useEffect(() => {
+    fetch("http://localhost:8080/api/students")
+      .then((res) => res.json())
+      .then((data) => setStudents(data));
+
+    fetch("http://localhost:8080/api/stages")
+      .then((res) => res.json())
+      .then((data) => setStages(data));
+
+    fetch("http://localhost:8080/api/univsupervisors") // Load supervisors
+      .then((res) => res.json())
+      .then((data) => setSupervisors(data));
+  }, []);
+
+  const handleChange = (e) => {
+    setFormData({ ...formData, [e.target.name]: e.target.value });
+  };
+
+  const handleSubmit = (e) => {
+    e.preventDefault();
+
+    fetch("http://localhost:8080/api/candidacies", {
+      method: "POST",
+      headers: { "Content-Type": "application/json" },
+      body: JSON.stringify({
+        student: { id: formData.studentId },
+        stage: { id: formData.stageId },
+        univSupervisor: { id: formData.univSupervisorId }, // Include supervisor
+      }),
+    })
+      .then((res) => res.json())
+      .then((data) => {
+        console.log("Candidacy added:", data);
+        alert("Candidacy added successfully!");
+      })
+      .catch((err) => console.error("Error:", err));
+  };
+
+  return (
+    <div className="container mt-4">
+      <h2>Ajouter une Candidature</h2>
+      <form onSubmit={handleSubmit}>
+        {/* Select Student */}
+        <div className="mb-3">
+          <label className="form-label">Étudiant:</label>
+          <select
+            className="form-control"
+            name="studentId"
+            value={formData.studentId}
+            onChange={handleChange}
+            required
+          >
+            <option value="">Sélectionnez un étudiant</option>
+            {students.map((student) => (
+              <option key={student.id} value={student.id}>
+                {student.firstname} {student.lastname}
+              </option>
+            ))}
+          </select>
+        </div>
+
+        {/* Select Stage */}
+        <div className="mb-3">
+          <label className="form-label">Stage:</label>
+          <select
+            className="form-control"
+            name="stageId"
+            value={formData.stageId}
+            onChange={handleChange}
+            required
+          >
+            <option value="">Sélectionnez un stage</option>
+            {stages.map((stage) => (
+              <option key={stage.id} value={stage.id}>
+                {stage.name} - {stage.description}
+              </option>
+            ))}
+          </select>
+        </div>
+
+        {/* Select UnivSupervisor */}
+        <div className="mb-3">
+          <label className="form-label">Superviseur Universitaire:</label>
+          <select
+            className="form-control"
+            name="univSupervisorId"
+            value={formData.univSupervisorId}
+            onChange={handleChange}
+            required
+          >
+            <option value="">Sélectionnez un superviseur</option>
+            {supervisors.map((supervisor) => (
+              <option key={supervisor.id} value={supervisor.id}>
+                {supervisor.name}
+              </option>
+            ))}
+          </select>
+        </div>
+
+        {/* Submit Button */}
+        <button type="submit" className="btn btn-primary">
+          Ajouter Candidature
+        </button>
+      </form>
+    </div>
+  );
+};
+
+export default CandidacyForm;