agent-platform release v4.15.5

Changed

• The agentgateway data plane moves to the line’s v1.5.1-gs.4 (agentgateway.proxy.image.tag in the connectivity chart, rendered into AgentgatewayParameters; giantswarm/giantswarm#37758): the Giant Swarm line of agentgateway re-pinned from upstream v1.5.0 onto upstream main @ c1d24607 (2026-09-14 — the substrate protocol of upstream #3237/#3318/#3409/#3428 that the Substrate line’s v0.0.29 router speaks; upstream has released nothing since v1.5.0), still carrying the GRPCRoute method-match translation and the resuming-actor admission. The giantswarm/agentgateway packaging chart moved the controller to the same release (giantswarm/agentgateway#52, released 2.1.2), so the data plane follows it here — controller and data plane are one build again. Proven in agentlab with both on gs.4 under 4.15.2: platform-test 7/7, a2a-test 5/5 (the GRPCRoute and its JWT policy through the edge), toolsets-test 11/11. Every installation with the agentgateway component on rolls its data-plane pods once. The Substrate and kagent line re-pins that belong to the same move follow in the next release.
• The three Bumblebee upstream lines re-pin together — agentgateway v1.5.1-gs.4, Substrate v0.0.30-gs.1, kagent v0.11.0-gs.14 (giantswarm/giantswarm#37742, #37010, #37757, #37758): components.substrate / components.substrate-crds move to >=0.0.30-gs.1 <0.0.31-0 (the Substrate line on upstream kagent-dev/substrate v0.0.29, its ten carried patches replayed — the egress gateway’s frontend policy is upstream’s own from v0.0.29 under agentgateway#3318’s name, kagent-dev/substrate#33 fell away — and its router and egress gateway on the agentgateway line’s v1.5.1-gs.4), components.kagent / components.kagent-crds to >=0.11.0-gs.14 <0.11.1-0 (the kagent line on upstream kagent-dev/kagent main @ 800015de, 2026-09-14 — kagent-dev/kagent#2802 moves kagent to Substrate v0.0.29 and its a2a gateway addresses an actor by the ate-target-actor header, which the 0.0.27 router did not know, so a kagent past #2802 on the previous Substrate fails every turn; the #2739 cherry-pick fell away, upstream has it — whose chart stamps the 0.0.30-gs.1 worker image) (the agentgateway line’s v1.5.1-gs.4 — upstream main @ c1d24607 — is the release the controller and data plane already run since the previous entry and the Substrate chart pins for its router). Proven in agentlab on the three lines’ dev builds together on this chart’s 4.15.2 (an upgrade from 0.0.27-gs.9 / 0.11.0-gs.13 / v1.5.1-gs.3): platform-test, agents-test, skills-test, toolsets-test, a2a-test and a headless turn through the edge. Every installation on the 4.x line rolls once: the Substrate control plane and the WorkerPool (the workers restart — an actor mid-turn on a rolled worker loses that turn, every golden snapshot is retaken on the new worker image), the kagent controller and UI — UPGRADE.md. BOM, tests/verify-components.py and tests/verify-kagent-crds.py follow the pins.