feat(admin): manage member account access

Allow administrators to freeze, unfreeze, and permanently delete member accounts with related content cleanup.

app.py

@@ -67,7 +67,8 @@ def init_db():
             is_approved INTEGER NOT NULL DEFAULT 0,
             role TEXT NOT NULL DEFAULT 'member',
             mfa_secret TEXT,
-            mfa_enabled INTEGER NOT NULL DEFAULT 0
+            mfa_enabled INTEGER NOT NULL DEFAULT 0,
+            is_frozen INTEGER NOT NULL DEFAULT 0
         );
         CREATE TABLE IF NOT EXISTS posts (
             id INTEGER PRIMARY KEY AUTOINCREMENT,
@@ -123,6 +124,7 @@ def init_db():
         "email": "ALTER TABLE users ADD COLUMN email TEXT",
         "email_verified": "ALTER TABLE users ADD COLUMN email_verified INTEGER NOT NULL DEFAULT 0",
         "real_name": "ALTER TABLE users ADD COLUMN real_name TEXT",
+        "is_frozen": "ALTER TABLE users ADD COLUMN is_frozen INTEGER NOT NULL DEFAULT 0",
     }
     post_columns = {row["name"] for row in db.execute("PRAGMA table_info(posts)")}
     for column, statement in migrations.items():
@@ -154,6 +156,11 @@ def login_required(view):
         if "user_id" not in session or not session.get("mfa_verified"):
             flash("Sign in to continue.", "notice")
             return redirect(url_for("login", next=request.path))
+        user = get_db().execute("SELECT is_frozen FROM users WHERE id = ?", (session["user_id"],)).fetchone()
+        if user is None or user["is_frozen"]:
+            session.clear()
+            flash("This account has been frozen by an administrator.", "error")
+            return redirect(url_for("login"))
         return view(*args, **kwargs)
 
     return wrapped_view
@@ -413,6 +420,8 @@ def login():
         user = get_db().execute("SELECT * FROM users WHERE username = ?", (username,)).fetchone()
         if user is None or not check_password_hash(user["password_hash"], request.form.get("password", "")):
             flash("Invalid handle or password.", "error")
+        elif user["is_frozen"]:
+            flash("This account has been frozen by an administrator.", "error")
         elif not user["is_approved"]:
             flash("Your account is awaiting administrator approval.", "notice")
         elif user["email"] and not user["email_verified"]:
@@ -637,7 +646,7 @@ def mfa_verify():
 @admin_required
 def admin_users():
     users = get_db().execute(
-        "SELECT id, username, real_name, email, email_verified, created_at, is_approved, mfa_enabled, role FROM users ORDER BY is_approved, created_at DESC"
+        "SELECT id, username, real_name, email, email_verified, created_at, is_approved, mfa_enabled, is_frozen, role FROM users ORDER BY is_frozen DESC, is_approved, created_at DESC"
     ).fetchall()
     return render_template("admin_users.html", users=users)
 
@@ -651,6 +660,48 @@ def approve_user(user_id):
     return redirect(url_for("admin_users"))
 
 
+@app.post("/admin/users/<int:user_id>/freeze")
+@admin_required
+def freeze_user(user_id):
+    cursor = get_db().execute("UPDATE users SET is_frozen = 1 WHERE id = ? AND role = 'member' AND is_frozen = 0", (user_id,))
+    get_db().commit()
+    flash("Account frozen." if cursor.rowcount else "No active member account was changed.", "success")
+    return redirect(url_for("admin_users"))
+
+
+@app.post("/admin/users/<int:user_id>/unfreeze")
+@admin_required
+def unfreeze_user(user_id):
+    cursor = get_db().execute("UPDATE users SET is_frozen = 0 WHERE id = ? AND role = 'member' AND is_frozen = 1", (user_id,))
+    get_db().commit()
+    flash("Account unfrozen." if cursor.rowcount else "No frozen member account was changed.", "success")
+    return redirect(url_for("admin_users"))
+
+
+@app.post("/admin/users/<int:user_id>/delete")
+@admin_required
+def delete_user(user_id):
+    db = get_db()
+    user = db.execute("SELECT id, username FROM users WHERE id = ? AND role = 'member'", (user_id,)).fetchone()
+    if user is None:
+        abort(404)
+    image_rows = db.execute(
+        """SELECT image_filename AS filename FROM posts WHERE author_id = ? AND image_filename IS NOT NULL
+           UNION SELECT post_images.filename FROM post_images JOIN posts ON posts.id = post_images.post_id WHERE posts.author_id = ?""",
+        (user_id, user_id),
+    ).fetchall()
+    db.execute("DELETE FROM post_images WHERE post_id IN (SELECT id FROM posts WHERE author_id = ?)", (user_id,))
+    db.execute("DELETE FROM posts WHERE author_id = ?", (user_id,))
+    db.execute("DELETE FROM password_reset_tokens WHERE user_id = ?", (user_id,))
+    db.execute("DELETE FROM email_verification_tokens WHERE user_id = ?", (user_id,))
+    db.execute("DELETE FROM users WHERE id = ?", (user_id,))
+    db.commit()
+    for image in image_rows:
+        (app.config["UPLOAD_FOLDER"] / image["filename"]).unlink(missing_ok=True)
+    flash(f"Account {user['username']} and its posts were permanently deleted.", "success")
+    return redirect(url_for("admin_users"))
+
+
 @app.post("/admin/users/<int:user_id>/password-reset")
 @admin_required
 def admin_password_reset(user_id):