Add health probe overrides to sidecar (#278)

Add support for overriding the health probes.
This is useful, for example, when injecting NetBird as a sidecar. In
that setup, the main container could start before NetBird has
established the VPN connection, resulting in failing to connect to
peers.

Example usage:
```yaml
apiVersion: netbird.io/v1alpha1
kind: SidecarProfile
metadata:
  name: netbird-sidecar
  labels:
spec:
  injectionMode: Sidecar
  setupKeyRef:
    name: netbird-setup-key
  containerOverride:
    startupProbe:
      exec:
        command: ["netbird", "status", "--check", "startup"]
      initialDelaySeconds: 10
      failureThreshold: 10
      periodSeconds: 5
```

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

* **New Features**
* SidecarProfile now supports overriding container health check probes
(startup, liveness, and readiness) for sidecar containers, enabling
fine-grained control over probe configurations.

* **Documentation**
* Updated API reference documentation with new probe override
configuration options.

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api/v1alpha1/sidecarprofile_types.go

@@ -53,6 +53,18 @@ type ContainerOverride struct {
 
 	// +optional
 	SecurityContext *corev1.SecurityContext `json:"securityContext,omitempty"`
+
+	// StartupProbe overrides the startup probe for the sidecar container.
+	// +optional
+	StartupProbe *corev1.Probe `json:"startupProbe,omitempty"`
+
+	// LivenessProbe overrides the liveness probe for the sidecar container.
+	// +optional
+	LivenessProbe *corev1.Probe `json:"livenessProbe,omitempty"`
+
+	// ReadinessProbe overrides the readiness probe for the sidecar container.
+	// +optional
+	ReadinessProbe *corev1.Probe `json:"readinessProbe,omitempty"`
 }
 
 // SidecarProfileStatus defines the observed state of SidecarProfile.

api/v1alpha1/zz_generated.deepcopy.go

@@ -27,6 +27,21 @@ func (in *ContainerOverride) DeepCopyInto(out *ContainerOverride) {
 		*out = new(v1.SecurityContext)
 		(*in).DeepCopyInto(*out)
 	}
+	if in.StartupProbe != nil {
+		in, out := &in.StartupProbe, &out.StartupProbe
+		*out = new(v1.Probe)
+		(*in).DeepCopyInto(*out)
+	}
+	if in.LivenessProbe != nil {
+		in, out := &in.LivenessProbe, &out.LivenessProbe
+		*out = new(v1.Probe)
+		(*in).DeepCopyInto(*out)
+	}
+	if in.ReadinessProbe != nil {
+		in, out := &in.ReadinessProbe, &out.ReadinessProbe
+		*out = new(v1.Probe)
+		(*in).DeepCopyInto(*out)
+	}
 }
 
 // DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new ContainerOverride.