fix: make index names unique across tables for PostgreSQL compatibility

PostgreSQL requires globally unique index names (unlike MySQL which scopes
them per table). Prefix generic names: idx_user→idx_al_user/idx_rt_user,
idx_token→idx_rt_token, idx_case/idx_code/idx_haupt→idx_icd_*.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/app/models/audit.py

@@ -81,9 +81,9 @@ class AuditLog(Base):
     user: Mapped[Optional["User"]] = relationship(foreign_keys=[user_id])
 
     __table_args__ = (
-        Index("idx_user", "user_id"),
-        Index("idx_entity", "entity_type", "entity_id"),
-        Index("idx_created", "created_at"),
+        Index("idx_al_user", "user_id"),
+        Index("idx_al_entity", "entity_type", "entity_id"),
+        Index("idx_al_created", "created_at"),
     )
 
 

backend/app/models/case.py

@@ -190,7 +190,7 @@ class CaseICDCode(Base):
     case: Mapped[Case] = relationship(back_populates="icd_codes")
 
     __table_args__ = (
-        Index("idx_case", "case_id"),
-        Index("idx_code", "icd_code"),
-        Index("idx_haupt", "icd_hauptgruppe"),
+        Index("idx_icd_case", "case_id"),
+        Index("idx_icd_code", "icd_code"),
+        Index("idx_icd_haupt", "icd_hauptgruppe"),
     )

backend/app/models/user.py

@@ -102,8 +102,8 @@ class RefreshToken(Base):
     user: Mapped[User] = relationship(back_populates="refresh_tokens")
 
     __table_args__ = (
-        Index("idx_user", "user_id"),
-        Index("idx_token", "token_hash"),
+        Index("idx_rt_user", "user_id"),
+        Index("idx_rt_token", "token_hash"),
     )