docs(readme): fix conformance table — getBalances is cross-plane MUST, not SHOULD (#73)

The top conformance-status table listed the 5 runtime ops that
`cycles-protocol-v0.yaml` marks OPTIONAL / nice-to-have as SHOULD.
That list wrongly included `getBalances`, contradicting the paragraph
a few lines below (and CONFORMANCE.md §MUST) which correctly classify
`getBalances` as a cross-plane MUST because
`cycles-governance-admin-v0.1.25.yaml` re-declares the same path +
operationId as normative.

Update the Normative (v0.1.25) row so the 4 true SHOULD ops
(`decide`, `listReservations`, `getReservation`, `createEvent`) stand
alone, and call out that `getBalances` is lifted to MUST via the
admin spec's re-declaration. Matches CONFORMANCE.md §MUST / Cross-plane
operations and the README's own §Conformance paragraph.

Docs-only; no spec, merged artifact, or changelog touched.

Author: amavashev

README.md

@@ -13,7 +13,7 @@ The Cycles spec suite is organized by conformance status. The **current conforma
 
 | Tier | Files | Status |
 |---|---|---|
-| **Normative (v0.1.25)** | [`cycles-protocol-v0.yaml`](cycles-protocol-v0.yaml) | A conformant server MUST implement the 4 core runtime ops (`createReservation`, `commitReservation`, `releaseReservation`, `extendReservation`); the 5 endpoints this spec marks OPTIONAL / nice-to-have (`decide`, `listReservations`, `getReservation`, `getBalances`, `createEvent`) are SHOULD. See [`CONFORMANCE.md`](CONFORMANCE.md). |
+| **Normative (v0.1.25)** | [`cycles-protocol-v0.yaml`](cycles-protocol-v0.yaml) | A conformant server MUST implement the 4 core runtime ops (`createReservation`, `commitReservation`, `releaseReservation`, `extendReservation`). Of the 5 endpoints this spec marks OPTIONAL / nice-to-have, `getBalances` is a cross-plane MUST because `cycles-governance-admin-v0.1.25.yaml` re-declares it as normative; the remaining 4 (`decide`, `listReservations`, `getReservation`, `createEvent`) are SHOULD. See [`CONFORMANCE.md`](CONFORMANCE.md). |
 | **Mixed (v0.1.25)** | [`cycles-governance-admin-v0.1.25.yaml`](cycles-governance-admin-v0.1.25.yaml) | Mostly runcycles' reference admin API (implementers MAY diverge), but eight cross-plane operations and selected schemas (`Event`, `EventType`, `EventData*`, `WebhookDelivery`, `WebhookRetryPolicy`, `Permission`) are normative via `x-conformance` labels. See [`CONFORMANCE.md`](CONFORMANCE.md). |
 | **Upcoming (v0.1.26)** | [`cycles-protocol-extensions-v0.1.26.yaml`](cycles-protocol-extensions-v0.1.26.yaml), [`cycles-action-kinds-v0.1.26.yaml`](cycles-action-kinds-v0.1.26.yaml), [`cycles-governance-extensions-v0.1.26.yaml`](cycles-governance-extensions-v0.1.26.yaml) | Published but not yet required for conformance. SHOULD today; will become MUST once the reference stack ships v0.1.26 support. |