fix(helm): make redisMasterHost self-contained so unittest CI passes

The previous version called common.names.fullname via .Subcharts.redis.
That template is only registered when the redis subchart is built into
charts/, but `helm unittest` (CI) renders the parent chart without
dependencies — so every test that renders deployment.yaml failed with
`no template "common.names.fullname"`.

Re-implement the subchart's fullname algorithm inline (pinned to
redis-16.11.2's common library): fullnameOverride wins, else
{release}-{nameOverride|"redis"} with the "release name contains redis"
collapse and trunc 63. No subchart dependency, identical output —
verified with charts/ removed (CI condition) and against the rendered
master Service name.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: sebastianiv21

deploy/helm/templates/_helpers.tpl

@@ -260,15 +260,23 @@ every `helm template`/install/upgrade.
 
 {{/*
 Redis: master service hostname (FQDN inside the cluster).
-Reuses the bundled `common.names.fullname` helper (the one the subchart's master
-Service uses), evaluated in the redis subchart's context (.Subcharts.redis), so the
-host always matches the Service it renders — including the edge cases where the
+Mirrors the Bitnami subchart's own `common.names.fullname` algorithm so the host
+always matches the master Service it renders — including the edge cases where the
 release name contains "redis" (the subchart collapses its fullname to just the
 release name) or redis.nameOverride / redis.fullnameOverride is set.
-Only valid when redis.enabled (the subchart context exists); all callers gate on it.
+
+Re-implemented here rather than calling `common.names.fullname` directly: that
+template is only registered when the redis subchart is built into charts/, which
+is not the case under `helm unittest` (it renders the parent chart without
+dependencies). Logic is pinned to redis-16.11.2's common library; revisit if the
+subchart is bumped.
 */}}
+{{- define "appsmith.redisFullname" -}}
+{{- $name := default "redis" .Values.redis.nameOverride -}}
+{{- .Values.redis.fullnameOverride | default (ternary .Release.Name (printf "%s-%s" .Release.Name $name) (contains $name .Release.Name)) | trunc 63 | trimSuffix "-" -}}
+{{- end -}}
 {{- define "appsmith.redisMasterHost" -}}
-{{- printf "%s-master.%s.svc.cluster.local" (include "common.names.fullname" .Subcharts.redis) (include "appsmith.namespace" .) -}}
+{{- printf "%s-master.%s.svc.cluster.local" (include "appsmith.redisFullname" .) (include "appsmith.namespace" .) -}}
 {{- end -}}
 
 {{/*