feat(activity): one Activity page — runs, admin actions, server log and quota under one filter bar

The audit log, the server log and the admin quota view were three pages (the quota one a Stats tab),
each with its own filters, and the background runs had no list at all. Now one page ("Napló" /
"Activity") reads all four, each still its own table on the server: a shared bar (text, a period of
1 h to 90 days defaulting to 7, an account) and each tab's own filters, the whole view in the URL.
The old page ids open their tab.

Server side: the audit log and the new run list (`/api/admin/runs`) filter and page like the server
log, through one keyset helper (`routes/_keyset`) the log now shares; an audit row keeps the request
it was made in (migration 0111), so its log lines are a pivot away, as a run's are (`lrun`). The
quota breakdown takes since/until and one account. The Scheduler rows get a history button to their
job's runs.

Also fixed on the way: re-saving the value in force on the Configuration page staged its override
without committing it (the commit sat inside the audit branch), so the save was lost.

backend/app/routes/admin_logs.py

@@ -8,33 +8,28 @@ What a row holds was redacted when it was written (`logs.record_fields`, and the
 browser's rows), so this serves the columns as they are; a value the redactor took out reads as
 `[redacted]` / `[email]`, which is the point — the console shows that something was there.
 
-Paging is a keyset over `(ts desc, id desc)`: a browser row's `ts` is clamped into its consent
-window, so `ts` alone is not unique, and an offset would skip or repeat rows while the writer adds
-new ones at the top. The live tail re-reads the first page rather than asking for "ids after N":
+Paging is a keyset over `(ts desc, id desc)` (`_keyset`). The live tail re-reads the first page rather than asking for "ids after N":
 several processes write this table, and a batch's ids are taken when it inserts, not when it
 commits, so a slower batch can land below an id the tail already passed — and would never show.
 """
 
-import base64
-import binascii
-import json
 from dataclasses import dataclass
-from datetime import datetime, timezone
+from datetime import datetime
 from typing import Literal
 
-from fastapi import APIRouter, Depends, HTTPException, Query
-from sqlalchemy import Text, and_, cast, func, or_, select
+from fastapi import APIRouter, Depends, Query
+from sqlalchemy import Text, cast, func, or_, select
 from sqlalchemy.orm import Session
 
 from app import logsink
 from app.auth import admin_user
 from app.db import get_db
 from app.models import LogEvent, User
+from app.routes._keyset import PAGE_MAX, accounts, older_than, page, utc
 from app.utils import like_escape
 
 router = APIRouter(prefix="/api/admin/logs", tags=["admin"])
 
-PAGE_MAX = 200
 # A facet list is a chip row, not a report: past this many distinct events the rest are reachable
 # through the free-text search, and the response stays small whatever a self-host logs.
 FACET_EVENTS_MAX = 100
@@ -47,35 +42,6 @@ Facet = Literal["levels", "sources", "user", "event"]
 NONE = "none"
 
 
-def _utc(value: datetime | None) -> datetime | None:
-    """A bound without a zone is UTC — the column is `timestamptz`, and a naive value would be read
-    in the database session's zone instead."""
-    if value is None or value.tzinfo is not None:
-        return value
-    return value.replace(tzinfo=timezone.utc)
-
-
-def _encode_cursor(row: LogEvent) -> str:
-    return base64.urlsafe_b64encode(json.dumps([row.ts.isoformat(), row.id]).encode()).decode()
-
-
-def _decode_cursor(cursor: str) -> tuple[datetime, int]:
-    try:
-        ts, row_id = json.loads(base64.urlsafe_b64decode(cursor.encode()))
-        return _utc(datetime.fromisoformat(ts)), int(row_id)
-    except (binascii.Error, json.JSONDecodeError, ValueError, TypeError) as exc:
-        raise HTTPException(status_code=400, detail={"code": "bad_cursor"}) from exc
-
-
-def _accounts(db: Session, user_ids: set[int]) -> dict[str, str]:
-    """The accounts a page names, by id → address. An id with no account left (erased after the
-    line was written) is simply absent, and the client shows the bare id."""
-    if not user_ids:
-        return {}
-    rows = db.execute(select(User.id, User.email).where(User.id.in_(user_ids))).all()
-    return {str(uid): email for uid, email in rows}
-
-
 @dataclass(frozen=True)
 class LogFilters:
     """The console's filters, shared by the page and its facet counts."""
@@ -117,9 +83,9 @@ class LogFilters:
         if self.run_id is not None:
             out.append(LogEvent.run_id == self.run_id)
         if self.since is not None:
-            out.append(LogEvent.ts >= _utc(self.since))
+            out.append(LogEvent.ts >= utc(self.since))
         if self.until is not None:
-            out.append(LogEvent.ts < _utc(self.until))
+            out.append(LogEvent.ts < utc(self.until))
         if self.q and self.q.strip():
             like = f"%{like_escape(self.q.strip())}%"
             out.append(
@@ -165,28 +131,20 @@ def list_logs(
     continues from a previous page's `next_cursor`."""
     query = select(LogEvent).where(*filters.conditions())
     if before is not None:
-        ts, row_id = _decode_cursor(before)
-        # The `ts <=` conjunct is implied by the OR; it is there so the planner can bound the
-        # `ts` index scan instead of filtering every newer row first.
-        query = query.where(
-            and_(
-                LogEvent.ts <= ts,
-                or_(LogEvent.ts < ts, and_(LogEvent.ts == ts, LogEvent.id < row_id)),
-            )
-        )
-
-    # One more than asked, to know whether there is a next page without a second count query.
-    rows = (
-        db.execute(query.order_by(LogEvent.ts.desc(), LogEvent.id.desc()).limit(limit + 1))
-        .scalars()
-        .all()
+        query = query.where(older_than(LogEvent.ts, LogEvent.id, before))
+    rows, cursor = page(
+        list(
+            db.execute(query.order_by(LogEvent.ts.desc(), LogEvent.id.desc()).limit(limit + 1))
+            .scalars()
+            .all()
+        ),
+        limit,
+        lambda r: r.ts,
     )
-    more = len(rows) > limit
-    rows = rows[:limit]
     return {
         "items": [logsink.serialize(r) for r in rows],
-        "accounts": _accounts(db, {r.user_id for r in rows if r.user_id is not None}),
-        "next_cursor": _encode_cursor(rows[-1]) if more else None,
+        "accounts": accounts(db, {r.user_id for r in rows if r.user_id is not None}),
+        "next_cursor": cursor,
     }
 
 
@@ -217,6 +175,6 @@ def log_facets(
         "sources": counts(LogEvent.source, "sources"),
         "events": counts(LogEvent.event, "event", FACET_EVENTS_MAX),
         "users": [{**u, "value": str(u["value"])} for u in users],
-        "accounts": _accounts(db, {u["value"] for u in users if u["value"] != NONE}),
+        "accounts": accounts(db, {u["value"] for u in users if u["value"] != NONE}),
         "total": db.scalar(total) or 0,
     }