chart+argocd: align tags to metadata-action semver output (no v prefix)

docker/metadata-action type=semver strips the leading v: git tag v0.1.0
produces image tag 0.1.0 on GHCR. Align both sides:
- imageupdater allowTags: ^[0-9]+\.[0-9]+\.[0-9]+$ (no v)
- values image.tag: 0.1.0 (was v0.1.0)

Author: MicheleCampi

argocd/imageupdater.yaml

@@ -17,7 +17,7 @@ spec:
           imageName: "ghcr.io/michelecampi/vllm-coldstart-operator"
           commonUpdateSettings:
             updateStrategy: "semver"
-            allowTags: "regexp:^v[0-9]+\\.[0-9]+\\.[0-9]+$"
+            allowTags: "regexp:^[0-9]+\.[0-9]+\.[0-9]+$"
             platforms:
               - "linux/amd64"
           manifestTargets:

chart/values.yaml

@@ -4,7 +4,7 @@
 #    via git write-back. When spec is set, the image helper uses it verbatim.
 image:
   repository: ghcr.io/michelecampi/vllm-coldstart-operator
-  tag: v0.1.0
+  tag: 0.1.0
   pullPolicy: IfNotPresent
   # -- Managed by ArgoCD Image Updater. Full image reference, takes precedence.
   spec: ghcr.io/michelecampi/vllm-coldstart-operator:latest@sha256:d7ccf8580f42a87ea401f13eed9188fc8892b07bd2212357e87c7919f71fb98d