docs(authentik): record the 7-day login-session TTL and add a setter script

The login-session lifetime (raised to days=7 on 2026-10-20) is owned by the
default-authentication-login stage's session_duration, not a global setting and
not SESSION_COOKIE_AGE. Authentik exposes no SESSION_SAVE_EVERY_REQUEST, so the
window is absolute. session_duration is a STRING idiom; a timedelta stores a form
timedelta_from_string rejects, crashing login. Add scripts/authentik-set-login-session-duration.sh
that validates the form before writing (DB state, not repo-managed, re-run after
a blueprint re-import). Trim the page back under the OKF 500-line cap. tests/run.sh green.

scripts/authentik-set-login-session-duration.sh

@@ -0,0 +1,47 @@
+#!/usr/bin/env bash
+# Set the authentik login-session TTL on Dankclaw.
+#
+# The login-session lifetime is governed by the `default-authentication-login`
+# stage's `session_duration`, NOT a global setting and NOT SESSION_COOKIE_AGE
+# (that is the pre-login session, sessions.unauthenticated_age). Authentik does
+# not expose SESSION_SAVE_EVERY_REQUEST at all, so the session is an absolute
+# window from login, not a sliding one.
+#
+# The field is a STRING in authentik's own idiom ("days=7", "seconds=30",
+# "hours=12") — not a Python timedelta. Writing str(timedelta(days=7)) stores
+# "7 days, 0:00:00", which authentik's timedelta_from_string parser REJECTS
+# (ValueError), and login then crashes computing the session expiry. Always pass
+# the "key=value" form; this script validates it before writing.
+#
+# Existing sessions keep their old expiry; the new TTL applies from the next
+# login. This is DB state — it is NOT repo-managed and a blueprint re-import or
+# rebuild-from-scratch reverts it. Run this again after such a rebuild.
+#
+# Usage: authentik-set-login-session-duration.sh ["days=7"]   (default days=7)
+set -euo pipefail
+
+DUR="${1:-days=7}"
+STAGE="default-authentication-login"
+HOST="${AUTHENTIK_HOST:-dankclaw}"
+
+# Refuse anything that is not the safe key=value duration idiom.
+if ! printf '%s' "$DUR" | grep -Eq '^[A-Za-z]+=[0-9]+([ ]+[A-Za-z]+=[0-9]+)*$'; then
+    echo "invalid duration '$DUR' — use authentik form, e.g. 'days=7' or 'seconds=30'" >&2
+    exit 2
+fi
+
+ssh "$HOST" 'podman exec -i authentik-server ak shell' <<PYEOF
+from django.apps import apps
+from authentik.lib.utils.time import timedelta_from_string
+dur = "$DUR"
+timedelta_from_string(dur)  # validate the form before touching the row
+ULS = apps.get_model("authentik_stages_user_login", "UserLoginStage")
+s = ULS.objects.get(name="$STAGE")
+s.session_duration = dur
+s.save(update_fields=["session_duration"])
+back = ULS.objects.get(name="$STAGE").session_duration
+assert back == dur, "persisted value mismatch: %r" % back
+print("session_duration set to", repr(back), "->", timedelta_from_string(back))
+PYEOF
+
+echo "Login-session TTL for '$STAGE' is now $DUR (applies on next login)."

serverAppConfigs-docs/Infrastructure/Authentik.md

@@ -267,6 +267,12 @@ The silent re-auth path was proven end-to-end: after deleting
 `qa-e2e-admin`'s rows, the e2e admin spec ran against the stale storage
 state and passed with no login prompt (2 tests, 2.9 s).
 
+## Login-session lifetime (how often you re-authenticate)
+
+How long a login stays valid is the **`default-authentication-login` stage's `session_duration`** (`UserLoginStage`) — not a global setting, and not `SESSION_COOKIE_AGE` (that is the *pre-login* session). Raised to **`days=7`** on 2026-10-20 (was stage value `0` = the 24 h framework default). It is an **absolute** window, never sliding: authentik implements `SESSION_SAVE_EVERY_REQUEST` nowhere, so activity does not extend it and no supported knob makes it one.
+
+**`session_duration` is a STRING** in authentik's idiom (`"days=7"`, `"seconds=30"`, `"hours=12"`). A Python `timedelta` stores `"7 days, 0:00:00"`, which `authentik.lib.utils.time.timedelta_from_string` rejects with `ValueError` and login then crashes computing the expiry — so set it with **`scripts/authentik-set-login-session-duration.sh`** (validates the form first). Any non-zero value applies to *every* login (the "remember me" box only adds `remember_me_offset` on top) and a positive `set_expiry` also overrides `SESSION_EXPIRE_AT_BROWSER_CLOSE`, so closing the browser no longer logs you out; **existing sessions keep their old expiry** — delete the user's `authentik_core_session`/`…proxysession` rows and re-login to force it now. This is **DB state, not repo-managed**: a blueprint re-import or rebuild reverts the stage to `0`, so re-run the script after one. The other two login stages (`default-source-*`) drive external-source/enrollment logins and stay at the framework default.
+
 ## Guard-chain flip recipe (adding a guarded vhost)
 
 Move a public vhost from `reverse_proxy <app>:<port>` onto the chain: