fix(apps): startupProbe initialDelaySeconds=20 to clear settle window

The original probe (periodSeconds: 2, failureThreshold: 30, no
initialDelay) silenced cold-start liveness/readiness *restarts* but
not the underlying "Unhealthy" Warning events — kubelet emits the
same event for startup, liveness, and readiness probe failures, and
the 2s period generates 5-7 failures during the ~13s cold start
instead of the chart-default 1-3 (periodSeconds: 10).

Merge-queue deploy of #1636 failed the check-event-warnings action,
which records a marker post-reconcile and fails if any Warning event
has lastTimestamp within a 90s settle window. The rollout these
patches force created new pods during that window; their startup
probes fired every 2s during cold start; their events landed past
the marker.

Set initialDelaySeconds: 20 (past the observed ~13s cold start) and
periodSeconds: 5 so the first probe lands on a serving container.
Zero failure events on a normal rollout; failureThreshold: 12 leaves
60s of grace if a container is unusually slow.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: devantler

k8s/bases/apps/actual-budget/helm-release.yaml

@@ -52,15 +52,20 @@ spec:
               # Chart hardcodes startupProbe absence; values override the
               # liveness/readiness blocks below but not startupProbe. Gate
               # liveness/readiness on the container actually serving HTTP.
+              # initialDelaySeconds skips past the ~10s cold-start window so
+              # the first probe lands on a serving container — zero failure
+              # events during the merge-queue's 90s steady-state Warning
+              # check.
               - op: add
                 path: /spec/template/spec/containers/0/startupProbe
                 value:
                   httpGet:
                     path: /
                     port: http
-                  periodSeconds: 2
-                  timeoutSeconds: 2
-                  failureThreshold: 30  # 60s max startup window
+                  initialDelaySeconds: 20
+                  periodSeconds: 5
+                  timeoutSeconds: 3
+                  failureThreshold: 12  # 60s grace beyond initial delay
   # https://github.com/community-charts/helm-charts/blob/main/charts/actualbudget/values.yaml
   values:
     replicaCount: ${actual_budget_replicas:=1}

k8s/bases/apps/headlamp/helm-release.yaml

@@ -77,15 +77,20 @@ spec:
               # 1-3 Unhealthy probe warnings while the Go binary initialises.
               # Add a startupProbe so liveness/readiness are gated until the
               # main container is actually serving.
+              # initialDelaySeconds skips past the cold-start window so the
+              # first probe lands on a serving container — zero failure
+              # events during the merge-queue's 90s steady-state Warning
+              # check.
               - op: add
                 path: /spec/template/spec/containers/0/startupProbe
                 value:
                   httpGet:
                     path: /
                     port: http
-                  periodSeconds: 2
-                  timeoutSeconds: 2
-                  failureThreshold: 30  # 60s max startup window
+                  initialDelaySeconds: 20
+                  periodSeconds: 5
+                  timeoutSeconds: 3
+                  failureThreshold: 12  # 60s grace beyond initial delay
           - target:
               kind: Deployment
               name: headlamp

k8s/bases/apps/homepage/helm-release.yaml

@@ -58,15 +58,22 @@ spec:
               # rollout produces 3 Unhealthy probe warnings per pod and leaves
               # only ~17s of headroom before the liveness restart fires. Add
               # a startupProbe to gate liveness/readiness during initial boot.
+              #
+              # initialDelaySeconds is past the observed ~13s cold start so
+              # the first probe lands on a serving container — zero failure
+              # events during a normal rollout (the merge-queue's 90s
+              # steady-state Warning check would otherwise count probe
+              # failures fired in that window).
               - op: add
                 path: /spec/template/spec/containers/0/startupProbe
                 value:
                   httpGet:
                     path: /
                     port: http
-                  periodSeconds: 2
-                  timeoutSeconds: 2
-                  failureThreshold: 30  # 60s max startup window
+                  initialDelaySeconds: 20
+                  periodSeconds: 5
+                  timeoutSeconds: 3
+                  failureThreshold: 12  # 60s grace beyond initial delay
   # ICONS:
   # https://github.com/walkxcode/dashboard-icons
   # https://simpleicons.org