fix(kamaji): increase memory limits and add startup probe (#2421)

## Summary

- Increase kamaji controller memory limit from 500Mi to 512Mi
- Increase kamaji controller memory request from 100Mi to 256Mi  
- Add startup probe with 60-second timeout (12 attempts × 5s periods)
- Increase readiness/liveness probe initialDelaySeconds from 5s/15s to
30s

## Problem

The kamaji controller was experiencing frequent CrashLoopBackOff due to
OOMKilled errors. Analysis showed:

- Container was being killed with exit code 137 (OOMKilled) after ~20-25
seconds of runtime
- Memory limit of 500Mi was insufficient for controller initialization
- Readiness probe was failing because it started too early (5s
initialDelay), before the controller finished leader election (~17s)

## Solution

**Memory increase:**
- Limit: 500Mi → 512Mi (based on production testing)
- Request: 100Mi → 256Mi (ensures adequate reservation)

**Startup probe:**
- Added to give controller up to 60 seconds to initialize without being
killed by liveness probe
- 12 attempts × 5s period = 60s maximum startup time

**Probe delays:**
- ReadinessProbe: 5s → 30s initialDelay (controller needs ~17s to
acquire leader lease)
- LivenessProbe: 15s → 30s initialDelay (aligned with readiness)

## Testing

Verified in production cluster:
- Controller runs stable with 0 restarts
- No more OOMKilled events
- Successfully creates kubeconfig secrets for tenant clusters

## Related Issues

Fixes tenant cluster components stuck in ContainerCreating due to
missing kubeconfig secrets (caused by crashing kamaji controller).

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

## Summary by CodeRabbit

* **Chores**
* Introduced automated health checks using HTTP-based probes to monitor
service status during startup, continuous operation, and readiness to
handle traffic.
* Adjusted container memory resource allocation for enhanced stability
and performance.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/system/kamaji/values.yaml

@@ -8,9 +8,32 @@ kamaji:
   resources:
     limits:
       cpu: 200m
-      memory: 500Mi
+      memory: 512Mi
     requests:
       cpu: 100m
-      memory: 100Mi
+      memory: 256Mi
+  startupProbe:
+    httpGet:
+      path: /healthz
+      port: healthcheck
+    initialDelaySeconds: 5
+    periodSeconds: 5
+    timeoutSeconds: 3
+    successThreshold: 1
+    failureThreshold: 12
+  livenessProbe:
+    httpGet:
+      path: /healthz
+      port: healthcheck
+    initialDelaySeconds: 30
+    periodSeconds: 20
+    timeoutSeconds: 1
+  readinessProbe:
+    httpGet:
+      path: /readyz
+      port: healthcheck
+    initialDelaySeconds: 30
+    periodSeconds: 10
+    timeoutSeconds: 1
   extraArgs:
     - --migrate-image=ghcr.io/cozystack/cozystack/kamaji:v1.3.0@sha256:8c9af083b60600c0800eb56a2cda75f26007b7272a1cf019140de003bfce1a4d