Make tokens revocable and move the refresh token out of localStorage (0.46.0)

F5 — A token was valid until it expired, full stop. Resetting a compromised
account's password changed nothing for whoever held its tokens (up to 30 days
for a refresh token), demoting or disabling an account only took effect once
the same clock ran out, and logout was purely client-side.

Every account now has a token_version, every token is minted carrying it, and
every request compares the two. Bumping it is the revoke switch, pulled on the
three changes that alter what an account may do: password, role, active flag.
"Sign out everywhere" in the user menu bumps your own. Plain "Sign out" only
drops the cookie, because signing out on your phone should not kill your
desktop session.

The refresh token left localStorage for an httpOnly cookie (SameSite=Lax,
scoped to /api/auth), and the access token is now held in memory only. A
successful XSS can still act inside the open page but can no longer walk off
with 30 days of access. The cookie is marked Secure only when the request
arrived over HTTPS — request.url.scheme is trustworthy since the F4 fix — so a
plain-HTTP homelab keeps working. Any refresh token an older build left in
localStorage is deleted on first load. Scripted clients that cannot hold a
cookie can still ask for it in the body with ?in_body=true.

F9 comes with it, as predicted: the WebSocket helpers read the role off the
live user instead of the token's claim. /ws/exec is root-equivalent on the
host, and a token minted while the account was an admin stayed syntactically
valid after a demotion.

The sharp edge was the migration, not the feature. _ensure_model_columns emits
ADD COLUMN without a DEFAULT, so SQLite would have filled token_version with
NULL on every existing install, every version check would have failed against
it, and the upgrade would have locked out every user everywhere. The helper now
renders NOT NULL DEFAULT <literal> for scalar defaults; test_schema_migration
builds a genuinely old-shaped user table and asserts the backfill. The version
comparison also tolerates NULL as 1, so a database migrated by some other route
still works.

Writing that test surfaced an undocumented precondition: _ensure_model_columns
does nothing unless `models` has been imported, since SQLModel.metadata is
empty until then. It holds in production because init_db imports first; now it
says so.

The authorization matrix did its job — adding two auth routes failed the suite
until both were classified, which is exactly the review moment it exists for.

30 new tests (698 total). Upgrading signs everyone out once.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Dk43rmEeRfYi5wsLDbmfyG

backend/database.py

@@ -4,6 +4,7 @@ from __future__ import annotations
 import logging
 import os
 from collections.abc import Generator
+from typing import Optional
 
 from sqlalchemy import inspect, text
 from sqlmodel import Session, SQLModel, create_engine
@@ -23,6 +24,27 @@ engine = create_engine(
 )
 
 
+def _default_literal(col) -> Optional[str]:
+    """SQL literal for a column's scalar default, or None if it has none.
+
+    Only plain values are rendered — a callable default (``default_factory``,
+    e.g. a timestamp) has no fixed literal, so those columns are added nullable
+    as before and filled by the ORM on the next write.
+    """
+    default = col.default
+    if default is None or not getattr(default, "is_scalar", False):
+        return None
+    value = default.arg
+    if isinstance(value, bool):
+        return "1" if value else "0"
+    if isinstance(value, (int, float)):
+        return str(value)
+    if isinstance(value, str):
+        escaped = value.replace("'", "''")
+        return f"'{escaped}'"
+    return None
+
+
 def _ensure_model_columns() -> None:
     """Add columns that models define but a pre-existing table is missing.
 
@@ -33,6 +55,15 @@ def _ensure_model_columns() -> None:
     model's columns against the live table and ``ADD COLUMN`` the safe
     (nullable, or defaulted) ones. Idempotent: on a fresh DB create_all already
     made every column, so this is a no-op.
+
+    Requires ``models`` to have been imported, or ``SQLModel.metadata`` is empty
+    and this silently does nothing. :func:`init_db` imports it first.
+
+    A column with a scalar default is added ``NOT NULL DEFAULT <value>`` so
+    existing rows are backfilled in the same statement. Without that clause
+    SQLite fills them with NULL, which is how a new non-nullable field turns
+    into a runtime surprise — for ``User.token_version`` it would have meant
+    every existing session failing its version check after the upgrade.
     """
     insp = inspect(engine)
     live_tables = set(insp.get_table_names())
@@ -52,8 +83,13 @@ def _ensure_model_columns() -> None:
                         "manual migration needed", table_name, col.name
                     )
                     continue
-                ddl_type = col.type.compile(dialect=engine.dialect)
-                conn.execute(text(f'ALTER TABLE "{table_name}" ADD COLUMN "{col.name}" {ddl_type}'))
+                ddl = f'ALTER TABLE "{table_name}" ADD COLUMN "{col.name}" '
+                ddl += col.type.compile(dialect=engine.dialect)
+                if (literal := _default_literal(col)) is not None:
+                    # Backfills existing rows and satisfies SQLite's rule that a
+                    # NOT NULL column may only be added together with a default.
+                    ddl += f" NOT NULL DEFAULT {literal}"
+                conn.execute(text(ddl))
                 logger.info("Schema migration: added column %s.%s", table_name, col.name)