v0.4.5

## 🚀 Announcing Agent Sandbox v0.4.5!
We're excited to announce the release of **Agent Sandbox v0.4.5**! This release brings significant improvements across release automation, Python SDK capabilities, core stability, and extensive documentation, making Agent Sandbox more robust and user-friendly.

### ⚠️ Breaking Changes

*   **Python SDK Update:** Upgraded GKE PodSnapshot API from `v1alpha1` to `v1`, which requires adding the `agents.x-k8s.io/sandbox-name-hash` label to your `PodSnapshotPolicy` grouping rules. Removed support for restoring sandboxes by creating new claims from previous snapshot templates. 

### Key Highlights

*   **CI/CD and Release Automation**
    A major overhaul of the release workflow introduces fully automated tagging (including graceful handling of release candidates and transitions to stable versions), enhanced release note generation with AI-powered summaries and accurate contributor listing, and robust image promotion to the `k8s.io` registry with PR polling. Workflow permissions have been refined, and all GitHub Actions dependencies updated for better reliability.
*   **Python SDK Improvements**
    The Python SDK now supports the stable `v1` version of the PodSnapshot API, ensuring better compatibility and introducing `sandboxNameHash` for snapshot grouping. A new Prometheus metric, `sandbox_client_discovery_latency_ms`, has been added to monitor client connection latency across different connection strategies. The SDK client now correctly accepts `warmpool` parameters for sandbox claim creation, resolving cross-namespace adoption issues, and the sandbox router efficiently streams large request bodies instead of buffering them.
*   **Enhanced Documentation and Examples**
    Documentation has been significantly expanded with new guides for `volumeClaimTemplates` and a quickstart for the Golang client. New examples showcase dynamic scaling of `SandboxWarmPool` with Horizontal Pod Autoscaler (HPA) and integration with Kueue for admission control and quota management (updated to `v1beta2` API). Documentation pages have been reordered and cleaned up for improved navigation, and a new PR template has been added to streamline contributions.
*   **Core Stability and Benchmarking**
    Memory leaks in the `extensions/controllers` package (including `SandboxClaimReconciler` and `SimpleSandboxQueue`) have been identified and fixed through the integration of `uber.org/goleak` for robust goroutine leak detection, enhancing long-term stability. Benchmarking capabilities are improved with CSV output for easier analysis and better Boskos resource tracking ensuring consistent GCR.io image pushes.
*   **Policy and Security Examples**
    New Kyverno policy examples have been added and hardened to prevent RBAC privilege escalation for Sandbox workloads, improving the security posture of your deployments.

### Installation

#### Core & Extensions
```bash
# To install only the core components:
kubectl apply -f https://github.com/kubernetes-sigs/agent-sandbox/releases/download/v0.4.5/manifest.yaml

# To install the extensions components:
kubectl apply -f https://github.com/kubernetes-sigs/agent-sandbox/releases/download/v0.4.5/extensions.yaml
```

#### Python SDK
```bash
pip install k8s-agent-sandbox==0.4.5
```
---
### Contributors

We extend our sincere thanks to all contributors to this release:
@ArthurKamalov, @CodesbyUnnati, @alimx07, @dependabot, @chw120, @drogovozDP, @janetkuo, @justinsb, @moficodes, @pandaji, @realshuting, @shrutiyam-glitch, @sohanpatil, @vicentefb, @volatilemolotov

#### 👋 New Contributors
@CodesbyUnnati made their first contribution in https://github.com/kubernetes-sigs/agent-sandbox/pull/684
@pandaji made their first contribution in https://github.com/kubernetes-sigs/agent-sandbox/pull/618
@sohanpatil made their first contribution in https://github.com/kubernetes-sigs/agent-sandbox/pull/715
@realshuting made their first contribution in https://github.com/kubernetes-sigs/agent-sandbox/pull/682

**Full Changelog**: https://github.com/kubernetes-sigs/agent-sandbox/compare/v0.4.3...v0.4.5