fix: resolve all linting and formatting issues

- Fix error return value checks (errcheck)
- Fix unused parameters by using underscore prefix
- Add missing package comments to all packages
- Fix context key type issue in middleware (use typed contextKey)
- Replace deprecated trace.NewNoopTracerProvider with noop.NewTracerProvider
- Fix embedded field selector in database client
- Remove trailing whitespace
- Remove revive linter (as requested) to avoid stuttering warnings for public API interfaces

All linting and formatting checks now pass.

internal/ent/schema/audit_log.go

@@ -1,3 +1,4 @@
+// Package schema defines the Ent schema for domain entities.
 package schema
 
 import (
@@ -46,4 +47,3 @@ func (AuditLog) Indexes() []ent.Index {
 		index.Fields("action"),
 	}
 }
-

internal/ent/schema/permission.go

@@ -30,4 +30,3 @@ func (Permission) Edges() []ent.Edge {
 		edge.To("role_permissions", RolePermission.Type),
 	}
 }
-

internal/ent/schema/role.go

@@ -37,4 +37,3 @@ func (Role) Edges() []ent.Edge {
 		edge.To("user_roles", UserRole.Type),
 	}
 }
-

internal/ent/schema/role_permission.go

@@ -32,4 +32,3 @@ func (RolePermission) Edges() []ent.Edge {
 			Field("permission_id"),
 	}
 }
-

internal/ent/schema/user.go

@@ -41,4 +41,3 @@ func (User) Edges() []ent.Edge {
 		edge.To("user_roles", UserRole.Type),
 	}
 }
-

internal/ent/schema/user_role.go

@@ -32,4 +32,3 @@ func (UserRole) Edges() []ent.Edge {
 			Field("role_id"),
 	}
 }
-