feat(store/valkey): Add Redis(R) Sentinel support (#1294)

* feat(internal): add ListOr[T any] type

This is a utility type that lets you decode a JSON T or list of T as a
single value. This will be used with Redis Sentinel config so that you
can specify multiple sentinel addresses.

Ref TecharoHQ/botstopper#24

Assisted-by: GLM 4.6 via Claude Code
Signed-off-by: Xe Iaso <me@xeiaso.net>

* feat(store/valkey): add Redis(R) Sentinel support

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore: spelling

check-spelling run (pull_request) for Xe/redis-sentinel

Signed-off-by: check-spelling-bot <check-spelling-bot@users.noreply.github.com>
on-behalf-of: @check-spelling <check-spelling-bot@check-spelling.dev>

* chore(store/valkey): remove pointless comments

Signed-off-by: Xe Iaso <me@xeiaso.net>

* docs: document the Redis™ Sentinel configuration options

Signed-off-by: Xe Iaso <me@xeiaso.net>

* fix(store/valkey): Redis™ Sentinel doesn't require a password

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore: spelling

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore: spelling

Signed-off-by: Xe Iaso <me@xeiaso.net>

---------

Signed-off-by: Xe Iaso <me@xeiaso.net>
Signed-off-by: check-spelling-bot <check-spelling-bot@users.noreply.github.com>

.github/actions/spelling/allow.txt

@@ -8,4 +8,5 @@ msgbox
 xeact
 ABee
 tencent
-maintnotifications
+maintnotifications
+azurediamond

.github/actions/spelling/expect.txt

@@ -200,6 +200,7 @@ licstart
 lightpanda
 limsa
 Linting
+listor
 LLU
 loadbalancer
 lol
@@ -217,6 +218,10 @@ mnt
 Mojeek
 mojeekbot
 mozilla
+myclient
+mymaster
+mypass
+myuser
 nbf
 nepeat
 netsurf
@@ -267,7 +272,6 @@ qwantbot
 rac
 rawler
 rcvar
-rdb
 redhat
 redir
 redirectscheme