Register a team UK gate signing key (hold: needs María's agreement)

changelog.d/uk-gate-team-signing-key.added.md

@@ -0,0 +1 @@
+Register a second UK gate signing key, held in the team's shared agent store, so cuts can be built and signed without the first builder's key. The key that signed every earlier cut stays active.

packages/microcosm-data/src/microcosm/data/gate_signing_keys.py

@@ -113,6 +113,25 @@ class GateSigningKey:
                 ),
             )
         ),
+        "dd31e32563854596d983a71a6519c6b7860a7c1f63ffb80dbe679d5d34c4de8c": (
+            GateSigningKey(
+                key_sha256=(
+                    "dd31e32563854596d983a71a6519c6b7860a7c1f63ffb80dbe679d5d34c4de8c"
+                ),
+                label="uk-gate-team-2026",
+                status="active",
+                custodian="the PolicyEngine team (Max Ghenis's shared agent store)",
+                held_in=(
+                    "agent-secret service microcosm/uk-gate-signing-key-team, "
+                    "account maxghenis, on Max's build Mac"
+                ),
+                registered="2026-10-22",
+                evidence=(
+                    "Generated 2026-10-22 for team-built cuts (microcosm#1348); "
+                    "never printed or committed."
+                ),
+            )
+        ),
     }
 )