feat(audit): rebuild the audit log as a grouped ledger with a drawer

Changes, Sign-ins, Security and All views replace the filter form. Repeats fold into one row,
sign-ins fold per person, day and network, and rows name their targets; events now snapshot
the target's name so deleted ones keep it. The drawer adds the event's facts, the target's
history, what the same person did around it, and one-click scoping. New additive routes:
/audit-log/summary, /sign-ins and /export; retention is editable from the page.

server/test/e2e/authorization-matrix/route-inventory/manifest.json

@@ -1,5 +1,5 @@
 {
-  "totalRoutes": 651,
+  "totalRoutes": 654,
   "byPermission": {
     "(none)": 283,
     "Permission.ManageMetadataConfig": 38,
@@ -15,7 +15,7 @@
     "Permission.DemoRestricted": 6,
     "Permission.KoreaderSync": 9,
     "Permission.OpdsAccess": 4,
-    "Permission.ViewAuditLog": 1,
+    "Permission.ViewAuditLog": 4,
     "Permission.ViewUserActivity": 6,
     "Permission.LibraryDeleteBooks": 14,
     "Permission.LibraryDownload": 4,

server/test/e2e/authorization-matrix/route-inventory/routes-01.json

@@ -275,6 +275,42 @@
     "allowDefault": false,
     "useGuards": []
   },
+  {
+    "file": "server/src/modules/audit/audit.controller.ts",
+    "className": "AuditController",
+    "methodName": "getSummary",
+    "httpMethod": "GET",
+    "path": "/audit-log/summary",
+    "permissions": ["Permission.ViewAuditLog"],
+    "libraryAccess": [],
+    "isPublic": false,
+    "allowDefault": false,
+    "useGuards": []
+  },
+  {
+    "file": "server/src/modules/audit/audit.controller.ts",
+    "className": "AuditController",
+    "methodName": "getSignIns",
+    "httpMethod": "GET",
+    "path": "/audit-log/sign-ins",
+    "permissions": ["Permission.ViewAuditLog"],
+    "libraryAccess": [],
+    "isPublic": false,
+    "allowDefault": false,
+    "useGuards": []
+  },
+  {
+    "file": "server/src/modules/audit/audit.controller.ts",
+    "className": "AuditController",
+    "methodName": "exportEvents",
+    "httpMethod": "GET",
+    "path": "/audit-log/export",
+    "permissions": ["Permission.ViewAuditLog"],
+    "libraryAccess": [],
+    "isPublic": false,
+    "allowDefault": false,
+    "useGuards": []
+  },
   {
     "file": "server/src/modules/auth/auth.controller.ts",
     "className": "AuthController",