feat(recibos): OCR capture for zona federal (ZOFEMAT Tijuana)

Adds the ZONA FEDERAL TIJUANA parser to the statement intake, measured
against 8 pages of real "Zona Federal Marítimo Terrestre" receipts — the
federal maritime-zone occupancy fee the municipality bills on beachfront
lots. Provider read on 8/8, amount on 8/8 (each verified against the
paper), concession clave on 6/8, period on 8/8, deadline on 2/8.

Four things the corpus forced:

- Tijuana bills predial and zona federal from the same treasury: same
  header, same Paseo del Centenario address, same ATB-541201 RFC. Every
  predial discriminator matches a zona federal page too, so whichever
  rule is asked first wins it. The only words exclusive to this layout
  are "Marítimo Terrestre", so its brand rule is asked ahead of all
  three predial ones — and its structural rule, anchored on the stub's
  "Derechos de ocupación", ahead of theirs.

- FEDERAL_ZONE.accountNumber is an amount, not a reference. It holds
  DATMEX.zfed, whose 77 values include 246.06, 2369.09, 22653.94 and a
  negative -1679, while the concession claves these receipts are keyed
  by appear nowhere in the database. Matching on that column could never
  hit — and because every row already has a value, the `[field]: null`
  guards on learnAccountRefs and on the review blank-service fill would
  never fire either, so every page would return to the queue every
  bimester forever. The clave moves to meterNumber, joining gas and
  Tijuana predial, and the first confirm teaches the match.

- The payable figure is not the printed subtotal. The municipality
  rounds to whole pesos and prints the difference on its own "Ajuste Ley
  Hacienda Mpal" line (-$0.05 against a 591.05 subtotal, $0.21 against
  2,872.79). The "Total a pagar" box carrying the rounded figure sits on
  a grey fill and OCR'd on 1 of 8 pages; the SubTotal row read on 8 of
  8. So the amount is the rounded subtotal, cross-checked against the
  printed box wherever it survives — where it did, it agreed.

- The clave is 2 digits, a letter and 3 digits (12-T -012), not the
  cadastral shape, and the letter is kept as printed: toDigits maps D to
  0, which turns a real 14-D -014 into 140014. It is printed twice,
  which rescued a page whose heading was struck through by the office's
  own highlighter — the failure mode behind both missing claves.

Deriving the deadline from the bimester is deliberately not attempted:
it is the 17th of the month after the bimester closes on a current bill,
but four of these eight are late (a $1,000 Multa) and print a
recalculated date, so a derived date would be wrong on exactly the pages
a human most wants to see.

Re-ran the earlier corpora (25 pages: predial Tijuana/Rosarito/Ensenada,
CFE, CESPT, Telnor) through detection to confirm the new rules steal
nothing — all 25 still read as their original provider, including the
five Tijuana predial pages that share the RFC.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

apps/api/src/statements/statement-matcher.service.ts

@@ -40,15 +40,22 @@ export interface MatchResult {
  * When they disagree, a reference gets learned into a column nothing searches,
  * and the same page returns to the review queue every month forever.
  *
- * `meterNumber` is doing double duty for the two kinds whose printed reference
- * DATMEX never held in `accountNumber`:
- *   - GAS, where the number lived in free-text notes, and
+ * `meterNumber` is doing double duty for the three kinds whose printed
+ * reference DATMEX never held in `accountNumber`:
+ *   - GAS, where the number lived in free-text notes,
  *   - PROPERTY_TAX, where `accountNumber` holds DATMEX.predial — a 3-4 digit
  *     office file number that is neither unique nor printed on any statement.
  *     The Tijuana municipal receipt prints an 8-digit account and no clave
  *     catastral at all, so it needs a column of its own; overwriting the legacy
  *     predial numbers to make room would destroy the only link back to the
- *     original records.
+ *     original records, and
+ *   - FEDERAL_ZONE, where `accountNumber` holds DATMEX.zfed, which is not a
+ *     reference of any kind but a peso amount: 3 of its 77 values carry cents
+ *     (`246.06`, `2369.09`, `22653.94`) and one is negative. Searching it for
+ *     the concession clave the receipt prints would never hit, and — worse —
+ *     because every row already has a value, the `[field]: null` guards in
+ *     `learnAccountRefs` and the blank-service fill would never fire either, so
+ *     the same page would return to the review queue every bimester forever.
  */
 export function scopedRefField(
   kind: ServiceKind,
@@ -57,11 +64,11 @@ export function scopedRefField(
     case "ELECTRIC": // CFE "NO. DE SERVICIO" -> DATMEX.rpu
     case "WATER": // CESPT "Cuenta" / "No. DE CUENTA" -> DATMEX.agua
     case "TELEPHONE": // Telnor "Teléfono" (LADA stripped) -> DATMEX.telefono
-    case "FEDERAL_ZONE":
     case "CABLE":
       return "accountNumber";
     case "GAS": // bajagas "Cuenta" -> recovered from notes into meterNumber
     case "PROPERTY_TAX": // Tijuana's 8-digit municipal account
+    case "FEDERAL_ZONE": // ZOFEMAT concession clave, e.g. `12T012`
       return "meterNumber";
     default:
       return null;