refactor(core): improve typing and test coverage

Restructure database and user CLI commands, make passwords write-only
model properties, and use the UTC datetime constant throughout the
application.

Add PEP 287-style documentation and expand receiver, scanner, sender,
and URL security tests to cover error paths and edge cases.

1 files changed, 10 insertions, 5 deletions

diff --git a/webmentions_ssg/models.py b/webmentions_ssg/models.py
index b6679e8..f89e587 100644
--- a/webmentions_ssg/models.py
+++ b/webmentions_ssg/models.py
@@ -1,7 +1,7 @@
 from __future__ import annotations
 
 import uuid
-from datetime import datetime, timezone
+from datetime import UTC, datetime
 from enum import StrEnum
 
 from flask_login import UserMixin
@@ -38,7 +38,12 @@ class User(UserMixin, Base):
     def __repr__(self) -> str:
         return f"<User {self.username}>"
 
-    def set_password(self, password: str) -> None:
+    @property
+    def password(self) -> None:
+        raise AttributeError("Password is write-only")
+
+    @password.setter
+    def password(self, password: str) -> None:
         self.password_hash = generate_password_hash(password)
 
     def check_password(self, password: str) -> bool:
@@ -60,8 +65,8 @@ class ReceivedWebmention(Base):
 
     updated_at: Mapped[datetime] = mapped_column(
         DateTime(timezone=True),
-        default=lambda: datetime.now(timezone.utc),
-        onupdate=lambda: datetime.now(timezone.utc),
+        default=lambda: datetime.now(UTC),
+        onupdate=lambda: datetime.now(UTC),
         nullable=False,
     )
 
@@ -185,4 +190,4 @@ class SentWebmention(Base):
 
 
 def uuid7_to_datetime(identifier: uuid.UUID) -> datetime:
-    return datetime.fromtimestamp(identifier.time / 1000, tz=timezone.utc)
+    return datetime.fromtimestamp(identifier.time / 1000, tz=UTC)