chore(images): refresh every registry pin to current upstream digest

Container images re-resolved against their registries today; each pin is the
manifest-list digest the tag answers now, so no container is served from a
build that upstream has already replaced.

Version-tag moves: authentik 2026.8.3 -> 2026.8.5 (server/worker/outpost and
the ldap image, which now carries the tag instead of a bare digest so the pair
can never drift apart), seerr v3.4.1 -> v3.5.1, calibre 9.15.0 -> 9.17.0,
calibre-web 0.6.27-ls402 -> ls407, plex ls329 -> ls330, tautulli
v2.18.1-ls245 -> v2.18.2-ls250.

Digest-only moves inside the same stream: postgres 16-alpine, mariadb 11,
redis 7-alpine, valkey 9-alpine, grafana, alertmanager, gluetun, searxng,
open-webui, jellyfin, romm, chromedp/headless-shell, lightpanda/browser.

Rollback is the previous digest on the same Image= line.

dankclaw/observability/quadlet/alertmanager.container

@@ -33,7 +33,7 @@ Wants=network-online.target
 
 [Container]
 ContainerName=alertmanager
-Image=docker.io/prom/alertmanager:latest@sha256:e9733bafb1bdef9b00e25a21f8f99dc26a22224bf16641ad754d1649f4c3357a
+Image=docker.io/prom/alertmanager:latest@sha256:39d8bb3966c694a124428a3a88fbcffd40bd069129ecd47c059f8a3f17c55f3b
 Network=dankclaw_default
 User=0:0
 Exec=--config.file=/etc/alertmanager/alertmanager.yml --storage.path=/alertmanager

dankclaw/observability/quadlet/grafana.container

@@ -34,7 +34,7 @@ Wants=network-online.target prometheus.service
 
 [Container]
 ContainerName=grafana
-Image=docker.io/grafana/grafana:latest@sha256:dbbc38ea21103cefb50396340cd88afec779c7e070b0a7bf5a75b4ce46651d3f
+Image=docker.io/grafana/grafana:latest@sha256:488984b716c0862639f91a698adbe2862677a5a07bad42da5f03f3030883b205
 Network=dankclaw_default
 User=0:0
 PublishPort=127.0.0.1:3002:3000