feat(controller): clusterconfig-schema-split task 5.1 — regenerate ha/data/cluster.bin fixture

Re-encodes the checked-in cluster.bin fixture against the renumbered
ClusterConfig schema (task 1.1), preserving all 13 retained fields'
semantic values byte-for-byte (verified via capnp convert round-trip and
independently reproduced in review) and dropping the 8 removed fields'
now-discarded values. deploy-ha.sh's verbatim-copy usage needs no changes.

Without this, every future /xce-deploy-ha and /xce-test-ha run would seed
ctrl-1 from a blob whose retained fields silently decode to wrong bytes
under the new schema.

.kiro/specs/clusterconfig-schema-split/tasks.md

@@ -70,7 +70,7 @@
   - _Depends: 1.1, 1.2, 1.3, 2.1, 2.2, 2.3, 3_
 
 - [ ] 5. Validation: Live HA Verification
-- [ ] 5.1 Regenerate the `ha/data/cluster.bin` fixture against the renumbered schema
+- [x] 5.1 Regenerate the `ha/data/cluster.bin` fixture against the renumbered schema
   - Decode the current (pre-spec) `ha/data/cluster.bin`'s retained-field values under the OLD (pre-renumbering) schema — build against a pre-1.1 checkout or otherwise capture the pre-spec field values before they become unreadable
   - Write and run a small throwaway capnp-encoding tool (not part of the shipped codebase — discard it after use) that constructs a `ClusterConfig` with those same retained-field values and serializes it under the NEW (post-task-1.1) schema
   - Overwrite `ha/data/cluster.bin` with the newly-encoded blob