fix: harden scheduler-k3s cron manifests and dockerfile run startup

The cron-id label could exceed Kubernetes' 63-byte cap when commands or
schedules were long, and an all-digit job-suffix or cron-id rendered as
an unquoted YAML scalar caused the API server to reject manifests. Run
pods built from dockerfiles also occasionally hit the 10s startup wait
on a cold image pull, even though the pod was scheduled correctly.

The cron-id is now stored as an annotation and a shorter hash is used as
the selector label. Every interpolated annotation and label value in the
cron-job and deployment templates is now quoted to prevent numeric
coercion, and the run-pod wait timeout is raised to 30 seconds.

plugins/scheduler-k3s/go.mod

@@ -22,6 +22,7 @@ require (
 	github.com/gosimple/slug v1.15.0
 	github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51
 	github.com/kedacore/keda/v2 v2.18.3
+	github.com/multiformats/go-base36 v0.2.0
 	github.com/ryanuber/columnize v2.1.2+incompatible
 	github.com/spf13/pflag v1.0.10
 	github.com/traefik/traefik/v2 v2.11.45
@@ -115,7 +116,6 @@ require (
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.3-0.20250322232337-35a7c28c31ee // indirect
 	github.com/monochromegane/go-gitignore v0.0.0-20200626010858-205db1a8cc00 // indirect
-	github.com/multiformats/go-base36 v0.2.0 // indirect
 	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
 	github.com/opencontainers/go-digest v1.0.0 // indirect
 	github.com/opencontainers/image-spec v1.1.1 // indirect