use a stable hash for the Booklore options cache key (#1079)

`_get_booklore_cache_key` returned
`f"{base_url}|{username}|{hash(password)}"`. Python's built-in `hash()`
is randomized per process (`PYTHONHASHSEED`), so the cache key for the
same Booklore credentials changed between every worker process and every
restart. If the dashboard was opened by a worker that landed on a
different seed than the worker that warmed the cache, the
`_BOOKLORE_OPTIONS_CACHE.get("key") == cache_key` check would miss on
every lookup, forcing a fresh `booklore_login` API call each time.

Switch to `hashlib.sha256(password.encode()).hexdigest()` —
deterministic across processes and restarts. SHA-256 is overkill for a
cache key, but matching the existing convention (`hashlib.sha1` is used
elsewhere in the codebase) is what we want here.

The password is already in memory (it comes from the request body /
`config.get`), so this doesn't introduce a new secret-handling concern.

Co-authored-by: Zo Bot <github-automation@zo.computer>

shelfmark/config/booklore_settings.py

@@ -3,6 +3,7 @@
 from __future__ import annotations
 
 from typing import Any
+import hashlib
 
 from shelfmark.core.config import config
 from shelfmark.core.logger import setup_logger
@@ -23,7 +24,7 @@ _BOOKLORE_OPTIONS_CACHE: dict[str, Any] = {
 
 
 def _get_booklore_cache_key(base_url: str, username: str, password: str) -> str:
-    return f"{base_url}|{username}|{hash(password)}"
+    return f"{base_url}|{username}|{hashlib.sha256(password.encode()).hexdigest()}"
 
 
 def _get_booklore_select_options(