Refactor: deplacer backend dans apps/backend

apps/backend/app/models/skill.py

@@ -0,0 +1,28 @@
+from sqlalchemy import Column, Integer, String
+from sqlalchemy.orm import relationship
+
+from app.database import Base
+from app.models.project_skill import project_skills
+
+
+class Skill(Base):
+    __tablename__ = "skills"
+
+    id = Column(Integer, primary_key=True, index=True)
+
+    name = Column(
+        String(255),
+        nullable=False,
+        unique=True
+    )
+
+    type = Column(
+        String(255),
+        nullable=False
+    )
+
+    projects = relationship(
+        "Project",
+        secondary=project_skills,
+        back_populates="skills"
+    )