agent-platform release v4.28.9

The two L4 presets fit the smallest L4 instance (giantswarm/agent-platform#502): qwen3-4b-instruct and qwen3-8b-fp8 request 2 vCPU / 10 GiB and are limited to 4 vCPU / 12 GiB (were 4 / 16Gi and 8 / 24Gi). A g6.xlarge has 4 vCPU and 16 GiB, of which a Giant Swarm node reports 3.4 vCPU / 13.4 GiB allocatable, and the daemonsets that follow a GPU pool’s taint request ~0.4 vCPU / 1.5 GiB more — on gazelle the predictor composed from qwen3-4b-instruct sat Pending for ten minutes on a pool of xlarge nodes (could not schedule pod … no instance type has enough resources … instance-size In [xlarge]) until the pool was widened to 2xlarge at +50 %/h (giantswarm/giantswarm#37714). The predictor’s host memory is the runtime and the weights passing through the page cache (the KV cache is on the GPU), so 10 GiB requested and 12 GiB limited cover an 8–9 GiB checkpoint. Each description names the instance it is sized for; tests/verify-serving-slice.py holds the requests within what a g6.xlarge leaves a predictor (the same node model cluster-manager’s create_node_pool answers with) and tests/verify-gpu-pool.py leaves the two preset ConfigMaps out of the byte-identity check against a golden from before.