refactor(v2): cassette models — position-keyed wire shape (#29 v1.1)

The wire format flips from
  {"denominations": {"<denom>": {"position", "count"}}}
to
  {"positions": {"<pos>": {"denomination", "count"}}}

per coord-log 2026-05-30T18:30Z + 18:45Z.

Per-row editable surface changes:
  - denomination becomes mutable (operator swaps cartridges during refill)
  - count remains mutable
  - position becomes the row identity (hardware bay number)

Removed: the no_duplicate_positions validator (no longer relevant — position
is the key, dups are impossible at the dict level) and the implicit
"denomination unique" assumption. Multiple positions with the same
denomination are now operationally valid per bitspire 18:45Z.

CassetteConfig model adds state_denomination (Optional[int]) for v2
reverse-channel reconciliation diff highlighting.

Tests under tests/test_cassette_configs.py and test_cassette_state_consumer.py
will fail at this commit — they reference the old denomination-keyed
shape. They get rewritten in v1.1 commit f. Branch tip is green only after
commit f lands; this and the next 3 commits are intermediate states.

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

models.py

@@ -549,41 +549,64 @@ class SettleBalanceData(BaseModel):
 
 
 # =============================================================================
-# Cassette configs — operator-driven ATM cassette inventory (#29).
+# Cassette configs — operator-driven ATM cassette inventory (#29 v1.1).
 # =============================================================================
-# Schema is denomination-keyed per the locked design (#29 body + the
+# Schema is position-keyed per the coordinated v1.1 redesign at coord-log
-# 06:40Z coord-log audit): every ATM-side layer below the wire keys on
+# 2026-05-30T18:30Z + 18:45Z. The earlier denomination-keyed shape (m007)
-# denomination (state-store.ts:54, hal-service.ts:116/189). The
+# was wrong: real machines have N cassettes of the same denomination for
-# satmachineadmin schema mirrors this so the operator UI can't author a
+# cash-out throughput, and operators need to swap cartridge denominations
-# duplicate-denomination payload that the ATM would silently collapse.
+# during refill ($20 bay becomes a $50 bay) without re-provisioning.
 #
-# Position is operator-assignable display order (and used by the ATM as
+# Wire shape:
-# the HAL slot-index assignment), not the addressable unit.
+#   {"positions": {"<position_str>": {"denomination": N, "count": M}}}
 #
-# state_count / state_at / state_event_id are reserved nullable from day 1
+# Editable surface per row:
-# for the v2 reverse-channel reconciliation consumer (bitspire-cassettes-
+#   - denomination: yes (operator swaps cartridges during refill)
-# state:<atm_pubkey_hex>). v1 populates them on bootstrap-event receipt
+#   - count: yes (refill / decrement)
-# but the UI doesn't render reconciliation.
+# Read-only per row:
+#   - position: hardware bay number; the slot count is fixed by the
+#     dispenser model (e.g., Tejo has 4 positions).
+#
+# No "denomination must be unique within payload" constraint: multiple
+# same-denom cassettes are operationally valid. The ATM HAL distributes
+# a dispense request greedy across all positions matching the requested
+# denomination (lamassu-next#56 v1.1 HAL refactor).
+#
+# state_* columns are reserved nullable 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. state_denomination (added in m008) lets v2 highlight
+# operator-believed-vs-ATM-reported denomination drift per slot.
 
 
 class CassetteConfig(BaseModel):
     machine_id: str
+    position: int
     denomination: int
     count: int
-    position: int
     updated_at: datetime
     updated_by: Optional[str]
+    state_denomination: Optional[int]
     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
+    """Operator edits a single cassette row's denomination or count from
-    dashboard. Both fields optional; pass only those changed."""
+    the dashboard. Both fields optional; pass only those changed.
+    Position is not edited — it's the row's identity (hardware bay)."""
 
+    denomination: Optional[int] = None
     count: Optional[int] = None
-    position: Optional[int] = None
+
+    @validator("denomination")
+    def denomination_positive(cls, v):
+        if v is None:
+            return v
+        if v <= 0:
+            raise ValueError("denomination must be > 0")
+        return v
 
     @validator("count")
     def count_non_negative(cls, v):
@@ -593,26 +616,18 @@ class UpsertCassetteConfigData(BaseModel):
             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
+    """One position's payload values in the wire-format
-    `{"denominations": {"<denom>": {"position", "count"}}}`."""
+    `{"positions": {"<pos>": {"denomination", "count"}}}`."""
 
-    position: int
+    denomination: int
     count: int
 
-    @validator("position")
+    @validator("denomination")
-    def position_positive(cls, v):
+    def denomination_positive(cls, v):
         if v <= 0:
-            raise ValueError("position must be > 0")
+            raise ValueError("denomination must be > 0")
         return v
 
     @validator("count")
@@ -628,45 +643,45 @@ class PublishCassettesPayload(BaseModel):
       - 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"}}}`.
+    Wire shape: `{"positions": {"<pos_str>": {"denomination", "count"}}}`.
     JSON object keys are always strings; the validator coerces back to
-    int on parse. The denomination key set MUST match what the receiver
+    int on parse. The position key set MUST match what the receiver
-    already has (no add / no remove from this payload).
+    already has (slot count is hardware-fixed; no add/remove from this
+    payload).
+
+    No denomination-unique constraint: multiple same-denom cassettes are
+    operationally valid (cash-out throughput on a popular denom).
     """
 
-    denominations: dict[int, CassettePayloadRow]
+    positions: dict[int, CassettePayloadRow]
 
-    @validator("denominations", pre=True)
+    @validator("positions", pre=True)
     def coerce_string_keys_to_int(cls, v):
         if not isinstance(v, dict):
-            raise ValueError("denominations must be a dict")
+            raise ValueError("positions 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"
+                    f"position key {k!r} is not an int"
                 ) from exc
             if key_int <= 0:
-                raise ValueError(f"denomination must be > 0 (got {key_int})")
+                raise ValueError(f"position 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": {
+            "positions": {
-                str(denom): {"position": row.position, "count": row.count}
+                str(pos): {
-                for denom, row in self.denominations.items()
+                    "denomination": row.denomination,
+                    "count": row.count,
+                }
+                for pos, row in self.positions.items()
             }
         }