Offer supply suggestions, drop the circuit column, center cells

The Versorgung field suggests ELT and MSR (plus values already used in
the balance) through a datalist and still accepts free text. The circuit
number column is not needed in early design phases; it is removed from
the data model, the regenerated migration 0010, the editor and the
print. All cells are centered except "Verbraucher / Flächen", group
titles and total labels.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/estimate-balance/domain/estimate-balance-command.model.ts

@@ -28,7 +28,6 @@ export const estimateRowSnapshotSchema = z
     id: idSchema,
     sortOrder: z.number().int().min(0),
     supply: nullableText(50),
-    circuitRef: nullableText(50),
     name: trimmed(200),
     quantity: finite.min(0),
     unit: z.enum(["piece", "area"]),
@@ -158,7 +157,6 @@ export function canonicalEstimateBalance(balance: EstimateBalanceSnapshot): stri
         id: row.id,
         sortOrder: row.sortOrder,
         supply: row.supply,
-        circuitRef: row.circuitRef,
         name: row.name,
         quantity: row.quantity,
         unit: row.unit,