feat!: probes link to the panel; signed release updates for container nodes [CI]

Probes connect to the panel directly and get the agent list as desired state.
CI signs the image digest of agent and probe releases, the panel forwards the
manifest, and a host updater verifies it with a local public key, pulls by
digest and rolls back when the new version is unhealthy.

.woodpecker/main-amd64-build.yml

@@ -36,6 +36,11 @@ steps:
       ZOT_USERNAME: justme
       ZOT_SECRET:
         from_secret: zot_secret
+      RELEASE_API_URL: https://mo.oeo.one
+      RELEASE_SIGNING_KEY:
+        from_secret: release_signing_key
+      RELEASE_API_TOKEN:
+        from_secret: release_api_token
     commands:
       - bash ci/build-main-amd64.sh agent
     depends_on: []
@@ -48,6 +53,11 @@ steps:
       ZOT_USERNAME: justme
       ZOT_SECRET:
         from_secret: zot_secret
+      RELEASE_API_URL: https://mo.oeo.one
+      RELEASE_SIGNING_KEY:
+        from_secret: release_signing_key
+      RELEASE_API_TOKEN:
+        from_secret: release_api_token
     commands:
       - bash ci/build-main-amd64.sh probe
     depends_on: []