✨ feat(deploy): Dockerfile + Helm chart for k3s homelab deployment

Pattern adapted from arcodange-org/webapp.

Degraded mode : no DB / no SMTP / no Vault yet, just serves the binary +
swagger + healthz. Subsequent PRs will add Vault auth + Postgres dynamic
credentials + SMTP config.

Ingress route : dancecoachlessons.arcodange.lab (homelab internal).

chart/values.yaml

@@ -0,0 +1,113 @@
+# Default values for dance-lessons-coach.
+# This is a YAML-formatted file.
+# Declare variables to be passed into your templates.
+
+replicaCount: 1
+
+image:
+  repository: gitea.arcodange.lab/arcodange/dance-lessons-coach
+  pullPolicy: Always
+  # Overrides the image tag whose default is the chart appVersion.
+  tag: ""
+
+imagePullSecrets: []
+nameOverride: ""
+fullnameOverride: ""
+
+serviceAccount:
+  # Specifies whether a service account should be created
+  create: true
+  # Automatically mount a ServiceAccount's API credentials?
+  automount: true
+  # Annotations to add to the service account
+  annotations: {}
+  # The name of the service account to use.
+  # If not set and create is true, a name is generated using the fullname template
+  name: ""
+
+podAnnotations: {}
+podLabels: {}
+
+podSecurityContext: {}
+  # fsGroup: 2000
+
+securityContext: {}
+  # capabilities:
+  #   drop:
+  #   - ALL
+  # readOnlyRootFilesystem: true
+  # runAsNonRoot: true
+  # runAsUser: 1000
+
+service:
+  type: ClusterIP
+  port: 8080
+
+ingress:
+  enabled: true
+  className: ""
+  annotations:
+    traefik.ingress.kubernetes.io/router.entrypoints: web
+    traefik.ingress.kubernetes.io/router.middlewares: kube-system-crowdsec@kubernetescrd
+  hosts:
+    - host: dancecoachlessons.arcodange.lab
+      paths:
+        - path: /
+          pathType: Prefix
+  tls: []
+
+resources: {}
+  # We usually recommend not to specify default resources and to leave this as a conscious
+  # choice for the user. This also increases chances charts run on environments with little
+  # resources, such as Minikube. If you do want to specify resources, uncomment the following
+  # lines, adjust them as necessary, and remove the curly braces after 'resources:'.
+  # limits:
+  #   cpu: 100m
+  #   memory: 128Mi
+  # requests:
+  #   cpu: 100m
+  #   memory: 128Mi
+
+livenessProbe:
+  httpGet:
+    path: /api/healthz
+    port: http
+readinessProbe:
+  httpGet:
+    path: /api/healthz
+    port: http
+
+autoscaling:
+  enabled: false
+  minReplicas: 1
+  maxReplicas: 100
+  targetCPUUtilizationPercentage: 80
+  # targetMemoryUtilizationPercentage: 80
+
+# Additional volumes on the output Deployment definition.
+volumes: []
+# - name: foo
+#   secret:
+#     secretName: mysecret
+#     optional: false
+
+# Additional volumeMounts on the output Deployment definition.
+volumeMounts: []
+# - name: foo
+#   mountPath: "/etc/foo"
+#   readOnly: true
+
+nodeSelector:
+  kubernetes.io/hostname: pi1
+
+tolerations: []
+
+affinity: {}
+
+# DLC-specific configuration
+config:
+  DLC_LOGGING_JSON: "true"
+  DLC_LOGGING_LEVEL: "info"
+  DLC_DATABASE_HOST: ""
+  DLC_DATABASE_PORT: "5432"
+  DLC_API_V2_ENABLED: "false"