feat(timeline): record a change by hand from the Timeline, a host's page or MCP log_change (#6350)

A change Steward can't see happen (a config edited, a disk swapped) is
recorded by whoever made it: what was done, its area, when (in the reader's
own zone), the hosts, what it was done to and a detail. Its author or an
admin edits or deletes it; recording, editing and deleting are audited and
those audit rows stay off the timeline. log_change records one as
"<user> via MCP", editable by the token's user.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

steward/timeline/routes.py

@@ -1,17 +1,20 @@
 from __future__ import annotations
 
-from quart import Blueprint, current_app, redirect, render_template, request, session, url_for
+from datetime import datetime, timezone
+from urllib.parse import urlencode
+
+from quart import Blueprint, abort, current_app, redirect, render_template, request, session, url_for
 from sqlalchemy import select
 
 from steward.audit.service import mark_day_groups
-from steward.auth.middleware import require_role
+from steward.auth.middleware import require_role, safe_next_url
 from steward.core import formatting as fmt
 from steward.core.audit import audit_request
 from steward.core.paging import keyset, next_page
 from steward.models.hosts import Host
 from steward.models.timeline import TimelineEntry
 from steward.models.users import UserRole
-from steward.timeline import catalog, config as tl_config, service as tl
+from steward.timeline import catalog, changes, config as tl_config, service as tl
 
 timeline_bp = Blueprint("timeline", __name__)
 
@@ -34,14 +37,15 @@ async def timeline():
                         include_hidden=f["hidden"])
         stmt = keyset(stmt, TimelineEntry.at, TimelineEntry.id, request.args.get("before"))
         rows, after = next_page((await db.execute(stmt)).scalars().all(), lambda e: (e.at, e.id))
-        items = await tl.views(db, cfg, rows)
+        items = _editable(await tl.views(db, cfg, rows))
         hosts = [] if request.args.get("before") else \
             list((await db.execute(select(Host.name).order_by(Host.name))).scalars())
     last_group = mark_day_groups(items, fmt.zone(session.get("tz")), request.args.get("group", ""),
                                  at=lambda item: item["entry"].at)
     keep = {k: v for k, v in (("host", f["host"]), ("area", f["area"]), ("kind", f["kind"]),
                               ("hidden", "1" if f["hidden"] else "")) if v}
-    ctx = {"items": items, "after": after, "last_group": last_group, "filters": f, "keep": keep,
+    back = "/timeline/" + ("?" + urlencode(keep) if keep else "")
+    ctx = {"items": items, "after": after, "last_group": last_group, "filters": f, "keep": keep, "back": back,
            "areas": cfg.areas, "kinds": catalog.KINDS,
            "hosts": hosts if not f["host"] or f["host"] in hosts else [f["host"], *hosts]}
     if request.args.get("before"):
@@ -58,10 +62,149 @@ async def host_card(host_id: str):
         if host is None:
             return "", 404
         cfg = await tl_config.load(db)
-        items = await tl.recent_for_host(db, cfg, host.name)
+        items = _editable(await tl.recent_for_host(db, cfg, host.name))
     return await render_template("timeline/_host_card.html", host=host, items=items)
 
 
+def _editable(items: list[dict]) -> list[dict]:
+    """Mark the entries this reader may edit: changes they recorded, or any as an admin."""
+    for item in items:
+        item["editable"] = changes.can_edit(item["entry"], session.get("user_id"), session.get("user_role"))
+    return items
+
+
+# ── Changes recorded by hand ────────────────────────────────────────────────
+
+def _local(value: str | None) -> datetime | None:
+    """A datetime-local field, in the reader's own zone."""
+    value = (value or "").strip()
+    if not value:
+        return None
+    try:
+        local = datetime.fromisoformat(value)
+    except ValueError:
+        raise ValueError(f"{value!r} is not a date and time.") from None
+    return local.replace(tzinfo=fmt.zone(session.get("tz"))).astimezone(timezone.utc)
+
+
+def _as_local(when: datetime) -> str:
+    return when.astimezone(fmt.zone(session.get("tz"))).strftime("%Y-%m-%dT%H:%M")
+
+
+async def _change_page(db, cfg, *, values: dict, entry=None, back: str, error: str | None = None,
+                       status: int = 200):
+    from steward.models.hosts import Host
+    hosts = list((await db.execute(select(Host.name).order_by(Host.name))).scalars())
+    # A host named by an entry and since removed stays ticked, so a save keeps it.
+    hosts += [h for h in values["hosts"] if h not in hosts]
+    return await render_template("timeline/change_form.html", values=values, entry=entry, back=back,
+                                 error=error, hosts=hosts, areas=cfg.areas), status
+
+
+def _back(raw: str | None) -> str:
+    """Where saving returns: the page the form was opened from, else the timeline."""
+    return safe_next_url(raw) or "/timeline/"
+
+
+async def _checked(db, cfg) -> tuple[dict | None, dict, str, str | None]:
+    """(fields, values, back, error) from the posted form: the fields
+    changes.fields checked, or None and why not, with the form's own values
+    to show again."""
+    form = await request.form
+    values = {"summary": form.get("summary", ""), "area": form.get("area", ""),
+              "hosts": form.getlist("hosts"), "subject": form.get("subject", ""),
+              "note": form.get("note", ""), "at": form.get("at", "")}
+    back = _back(form.get("back"))
+    try:
+        f = await changes.fields(db, cfg, summary=values["summary"], area=values["area"],
+                                 hosts=values["hosts"], subject=values["subject"],
+                                 note=values["note"], at=_local(values["at"]))
+    except ValueError as exc:
+        return None, values, back, str(exc)
+    return f, values, back, None
+
+
+@timeline_bp.get("/timeline/changes/new")
+@require_role(UserRole.operator)
+async def new_change():
+    """The form for recording a change; ?host= ticks a host, ?back= is where saving returns."""
+    host = request.args.get("host", "").strip()
+    values = {"summary": "", "area": "", "hosts": [host] if host else [], "subject": "", "note": "",
+              "at": _as_local(datetime.now(timezone.utc))}
+    async with current_app.db_sessionmaker() as db:
+        cfg = await tl_config.load(db)
+        return await _change_page(db, cfg, values=values, back=_back(request.args.get("back")))
+
+
+@timeline_bp.post("/timeline/changes")
+@require_role(UserRole.operator)
+async def record_change():
+    async with current_app.db_sessionmaker() as db:
+        async with db.begin():
+            cfg = await tl_config.load(db)
+            f, values, back, error = await _checked(db, cfg)
+            if error:
+                return await _change_page(db, cfg, values=values, back=back, error=error, status=400)
+            entry = changes.log(db, f, author_id=session.get("user_id"), actor=session.get("username", ""))
+    await audit_request("timeline.change_recorded", entity_type="timeline_entry", entity_id=entry.id,
+                        detail={"name": entry.summary, "hosts": entry.hosts, "area": entry.area})
+    return redirect(back)
+
+
+async def _own(db, entry_id: str):
+    """The recorded change `entry_id`, when this reader may edit it; else 404 or 403."""
+    entry = await changes.get(db, entry_id)
+    if entry is None:
+        abort(404)
+    if not changes.can_edit(entry, session.get("user_id"), session.get("user_role")):
+        abort(403)
+    return entry
+
+
+@timeline_bp.get("/timeline/changes/<entry_id>/edit")
+@require_role(UserRole.operator)
+async def edit_change(entry_id: str):
+    async with current_app.db_sessionmaker() as db:
+        entry = await _own(db, entry_id)
+        cfg = await tl_config.load(db)
+        values = {"summary": entry.summary, "area": entry.area, "hosts": list(entry.hosts),
+                  "subject": entry.subject or "", "note": (entry.detail or {}).get("note") or "",
+                  "at": _as_local(entry.at)}
+        return await _change_page(db, cfg, values=values, entry=entry,
+                                  back=_back(request.args.get("back")))
+
+
+@timeline_bp.post("/timeline/changes/<entry_id>")
+@require_role(UserRole.operator)
+async def save_change(entry_id: str):
+    async with current_app.db_sessionmaker() as db:
+        async with db.begin():
+            entry = await _own(db, entry_id)
+            cfg = await tl_config.load(db)
+            f, values, back, error = await _checked(db, cfg)
+            if error:
+                return await _change_page(db, cfg, values=values, entry=entry, back=back,
+                                          error=error, status=400)
+            changes.edit(entry, f)
+    await audit_request("timeline.change_edited", entity_type="timeline_entry", entity_id=entry_id,
+                        detail={"name": f["summary"]})
+    return redirect(back)
+
+
+@timeline_bp.post("/timeline/changes/<entry_id>/delete")
+@require_role(UserRole.operator)
+async def delete_change(entry_id: str):
+    form = await request.form
+    async with current_app.db_sessionmaker() as db:
+        async with db.begin():
+            entry = await _own(db, entry_id)
+            summary = entry.summary
+            await db.delete(entry)
+    await audit_request("timeline.change_deleted", entity_type="timeline_entry", entity_id=entry_id,
+                        detail={"name": summary})
+    return redirect(_back(form.get("back")))
+
+
 @timeline_bp.get("/settings/timeline/")
 @require_role(UserRole.admin)
 async def settings_page():