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/db/migrations/meta/0010_snapshot.json

@@ -1,7 +1,7 @@
 {
   "version": "6",
   "dialect": "sqlite",
-  "id": "6df688bd-a78a-46a1-ba7a-4068119bf8bd",
+  "id": "5376ae9f-67c7-4603-b3d2-8527136436f9",
   "prevId": "2cd9adef-2f08-4635-b3d9-ecf71f624c7f",
   "tables": {
     "buildings": {
@@ -1322,13 +1322,6 @@
           "notNull": false,
           "autoincrement": false
         },
-        "circuit_ref": {
-          "name": "circuit_ref",
-          "type": "text",
-          "primaryKey": false,
-          "notNull": false,
-          "autoincrement": false
-        },
         "name": {
           "name": "name",
           "type": "text",