feat(v2): m007 cassette_configs schema + Pydantic models (#29 v1)

Add the operator-side schema for per-machine ATM cassette inventory
(aiolabs/satmachineadmin#29). Schema choice mirrors the ATM-side
denomination-as-key invariant audited at coord-log 2026-05-30T06:40Z
across bitspire/atm-tui/src/db.zig:31, lamassu-next state-store.ts:54,
and hal-service.ts:116/189 — every ATM layer keys on denomination, so
the operator-side PK is (machine_id, denomination) to make
duplicate-denomination payloads impossible at the schema boundary.

Reserved nullable columns (state_count, state_at, state_event_id) hold
the latest bitspire-cassettes-state:<atm_pubkey_hex> event the ATM
publishes. v1 populates them on bootstrap-event receipt; v1 UI doesn't
render reconciliation. v2 reconciliation UI consumes them without a
migration.

Pydantic models in this commit:
  - CassetteConfig — read model for a stored row
  - UpsertCassetteConfigData — operator-edit form (count and/or position)
  - CassettePayloadRow — one denomination's wire-format values
  - PublishCassettesPayload — the full kind-30078 content payload,
    bidirectional (operator → ATM and ATM → operator share the shape).
    Validates int-coerced denomination keys, positive ints, no duplicate
    positions, and exposes to_wire_dict() that re-stringifies keys for
    JSON compatibility.

CRUD + transport + API + UI land in subsequent commits.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

models.py

@@ -546,3 +546,127 @@ class SettleBalanceData(BaseModel):
         if v <= 0:
             raise ValueError("amount_fiat must be > 0 if specified")
         return round(float(v), 2)
+
+
+# =============================================================================
+# Cassette configs — operator-driven ATM cassette inventory (#29).
+# =============================================================================
+# Schema is denomination-keyed per the locked design (#29 body + the
+# 06:40Z coord-log audit): every ATM-side layer below the wire keys on
+# denomination (state-store.ts:54, hal-service.ts:116/189). The
+# satmachineadmin schema mirrors this so the operator UI can't author a
+# duplicate-denomination payload that the ATM would silently collapse.
+#
+# Position is operator-assignable display order (and used by the ATM as
+# the HAL slot-index assignment), not the addressable unit.
+#
+# state_count / state_at / state_event_id are reserved nullable from day 1
+# for the v2 reverse-channel reconciliation consumer (bitspire-cassettes-
+# state:<atm_pubkey_hex>). v1 populates them on bootstrap-event receipt
+# but the UI doesn't render reconciliation.
+
+
+class CassetteConfig(BaseModel):
+    machine_id: str
+    denomination: int
+    count: int
+    position: int
+    updated_at: datetime
+    updated_by: Optional[str]
+    state_count: Optional[int]
+    state_at: Optional[datetime]
+    state_event_id: Optional[str]
+
+
+class UpsertCassetteConfigData(BaseModel):
+    """Operator edits a single cassette row's count or position from the
+    dashboard. Both fields optional; pass only those changed."""
+
+    count: Optional[int] = None
+    position: Optional[int] = None
+
+    @validator("count")
+    def count_non_negative(cls, v):
+        if v is None:
+            return v
+        if v < 0:
+            raise ValueError("count must be >= 0")
+        return v
+
+    @validator("position")
+    def position_positive(cls, v):
+        if v is None:
+            return v
+        if v <= 0:
+            raise ValueError("position must be > 0")
+        return v
+
+
+class CassettePayloadRow(BaseModel):
+    """One denomination's payload values in the wire-format
+    `{"denominations": {"<denom>": {"position", "count"}}}`."""
+
+    position: int
+    count: int
+
+    @validator("position")
+    def position_positive(cls, v):
+        if v <= 0:
+            raise ValueError("position must be > 0")
+        return v
+
+    @validator("count")
+    def count_non_negative(cls, v):
+        if v < 0:
+            raise ValueError("count must be >= 0")
+        return v
+
+
+class PublishCassettesPayload(BaseModel):
+    """The decrypted JSON content of a kind-30078 cassette event, both
+    directions:
+      - operator → ATM   (d-tag `bitspire-cassettes:<atm_pubkey_hex>`)
+      - ATM → operator   (d-tag `bitspire-cassettes-state:<atm_pubkey_hex>`)
+
+    Wire shape: `{"denominations": {"<denom_str>": {"position", "count"}}}`.
+    JSON object keys are always strings; the validator coerces back to
+    int on parse. The denomination key set MUST match what the receiver
+    already has (no add / no remove from this payload).
+    """
+
+    denominations: dict[int, CassettePayloadRow]
+
+    @validator("denominations", pre=True)
+    def coerce_string_keys_to_int(cls, v):
+        if not isinstance(v, dict):
+            raise ValueError("denominations must be a dict")
+        out = {}
+        for k, val in v.items():
+            try:
+                key_int = int(k)
+            except (TypeError, ValueError) as exc:
+                raise ValueError(
+                    f"denomination key {k!r} is not an int"
+                ) from exc
+            if key_int <= 0:
+                raise ValueError(f"denomination must be > 0 (got {key_int})")
+            out[key_int] = val
+        return out
+
+    @validator("denominations")
+    def no_duplicate_positions(cls, v):
+        positions = [row.position for row in v.values()]
+        if len(set(positions)) != len(positions):
+            raise ValueError("duplicate position values in payload")
+        return v
+
+    def to_wire_dict(self) -> dict:
+        """Serialise back to the wire format with string keys for JSON
+        object compatibility. Used by the publisher to build the kind-30078
+        event content before NIP-44 v2 encryption."""
+        return {
+            "denominations": {
+                str(denom): {"position": row.position, "count": row.count}
+                for denom, row in self.denominations.items()
+            }
+        }