Stage A of review fixes: single read snapshot, redacted /health, batched diff

/addresses reads the cursor and data in one session and one snapshot,
/health exposes only time and backup file name of the last restore,
get_changes checks presence in batches instead of per value (6.8 s -> 88 ms
on a 12k-entry journal). Adds the plan for review fixes 5-10.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

api_server.py

@@ -6,7 +6,7 @@ import os
 import re
 import secrets
 import sqlite3
-from typing import List, Literal, Optional
+from typing import Literal, Optional
 
 from apscheduler.triggers.cron import CronTrigger
 from fastapi import Depends, FastAPI, Header, HTTPException, Path, Query, Response
@@ -121,16 +121,6 @@ def ensure_data_ready(conn, kinds):
                             detail="The database was recreated after corruption; data is being collected again.")
 
 
-def get_cidrs() -> List[str]:
-    with db.session() as conn:
-        return db.get_values(conn, "asn")
-
-
-def get_fqdn_ips() -> List[str]:
-    with db.session() as conn:
-        return db.get_values(conn, "fqdn")
-
-
 @app.get("/addresses", response_model=None, responses={
     200: {"description": "JSON list for format=json, text/plain configuration script for other formats",
           "content": {"application/json": {"schema": {"type": "array", "items": {"type": "string"}}},
@@ -144,17 +134,14 @@ def get_addresses(
                       description="List/set name used in generated configuration"),
     response: Response = None,
 ):
-    # Курсор читаем до данных: изменения между чтением курсора и данных повторятся в diff, что безвредно
-    with db.session() as conn:
-        ensure_data_ready(conn, kinds_of(type))
-        headers = {"X-Changes-Cursor": str(db.journal_head(conn))}
+    # Одна сессия и один снимок: курсор в заголовке точно соответствует выданным данным
+    kinds = kinds_of(type)
     results = set()
-
-    if type in [AddressType.cidr, AddressType.all_types]:
-        results.update(get_cidrs())
-
-    if type in [AddressType.fqdn, AddressType.all_types]:
-        results.update(get_fqdn_ips())
+    with db.session() as conn, db.read_transaction(conn):
+        ensure_data_ready(conn, kinds)
+        headers = {"X-Changes-Cursor": str(db.journal_head(conn))}
+        for kind in kinds:
+            results.update(db.get_values(conn, kind))
 
     output = formatters.build_output(results, format.value, ip_version.value, aggregate, name)
     if format == OutputFormat.json:
@@ -233,9 +220,12 @@ def health():
         pending = db.recreated_pending(conn, ("asn", "fqdn"))
 
     try:
-        last_restore = load_json(cc.RESTORE_FILE, None)  # след автовосстановления базы из копии
+        restore = load_json(cc.RESTORE_FILE, None)  # след автовосстановления базы из копии
     except StorageError:
-        last_restore = None
+        restore = None
+    # Наружу - только время и имя файла копии; каталоги и текст ошибки остаются в last_restore.json
+    last_restore = ({"at": restore.get("at"), "backup": os.path.basename(str(restore.get("backup") or ""))}
+                    if isinstance(restore, dict) else None)
 
     try:
         recreated = load_json(cc.RECREATED_FILE, None)  # база пересоздана после порчи без копий