M12b: category contract v2 on the server (schema 2, fourteen defaults, finer import mapping)

- migrations/0002_categories_v2.sql, byte-identical to contracts/schema/migrations/0002_categories_v2.sql
  (SPEC §14.1.1), with an identity test; SCHEMA_VERSION = 2 (E-1 reports it, the importer's check follows).
- Seed test on a fresh database (the fourteen rows of AC-7.2, server_version 11 to 14) and an upgrade test of a
  v1 database in use (0001 applied through the migrator, then users, a custom, a renamed and an archived default,
  an account, a recurring template, expenses): every earlier row unchanged, the four rows above the old
  sequence, foreign_key_check empty, schema_version 2, a pull from the old cursor returns exactly the four rows.
- DefaultCategoryKey with the fourteen keys (wire enum and contracts/openapi.yaml); icons 33 and colours 14
  (§9.7) in validation.
- The two category examples M12a held back (E-26 response-default, sync/pull-page-categories-v2) and its
  contracts-check patch for them and the enum.
- Importer: splitwise_categories.csv per the §10.8 v0.8 table (D-053), DEFAULT_KEYS of fourteen, synthetic
  fixtures for the finer mapping (Insurance/Försäkringar to insurance among them), a schema-1 refusal test.
- Test harnesses seed users at server_version 15/16 (after the fourteen seeds); pull counts 10 -> 14.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TQd3pEP9UeN2uifbHknQ7B

server/crates/kvitt-import/data/splitwise_categories.csv

@@ -3,12 +3,12 @@ Groceries,en,groceries
 Food and drink - Other,en,groceries
 Liquor,en,groceries
 Dining out,en,restaurants
+Rent,en,housing
+Mortgage,en,housing
 Electronics,en,home
 Furniture,en,home
 Household supplies,en,home
 Maintenance,en,home
-Mortgage,en,home
-Rent,en,home
 Services,en,home
 Pets,en,home
 Home - Other,en,home
@@ -19,6 +19,7 @@ Trash,en,utilities
 TV/Phone/Internet,en,utilities
 Cleaning,en,utilities
 Utilities - Other,en,utilities
+Insurance,en,insurance
 Bicycle,en,transport
 Bus/train,en,transport
 Car,en,transport
@@ -34,30 +35,35 @@ Music,en,entertainment
 Sports,en,entertainment
 Entertainment - Other,en,entertainment
 Medical expenses,en,health
+Childcare,en,children
 Clothing,en,shopping
 Gifts,en,shopping
+Taxes,en,fees
 General,en,other
-Childcare,en,other
 Education,en,other
-Insurance,en,other
-Taxes,en,other
 Life - Other,en,other
 Other,en,other
 Livsmedel,sv,groceries
 Mat och dryck - Övrigt,sv,groceries
 Alkohol,sv,groceries
 Restaurangbesök,sv,restaurants
+Hyra,sv,housing
+Avbetalning/Amortering,sv,housing
 Elektronik,sv,home
 Möbler,sv,home
 Förbrukningsvaror,sv,home
 Skötsel/underhåll,sv,home
-Avbetalning/Amortering,sv,home
-Hyra,sv,home
 Tjänster,sv,home
+Husdjur,sv,home
 Hem - Övrigt,sv,home
+El,sv,utilities
+Värme/gas,sv,utilities
+Vatten,sv,utilities
+Sophämtning,sv,utilities
 TV/telefon/internet,sv,utilities
 Städning,sv,utilities
 Verktyg - Övrigt,sv,utilities
+Försäkringar,sv,insurance
 Cykel,sv,transport
 Buss/tåg,sv,transport
 Bil,sv,transport
@@ -68,16 +74,15 @@ Transport - Övrigt,sv,transport
 Hotell,sv,travel
 Flyg,sv,travel
 Spel,sv,entertainment
-Musik,sv,entertainment
 Filmer,sv,entertainment
+Musik,sv,entertainment
 Sport,sv,entertainment
 Underhållning - Övrigt,sv,entertainment
 Sjukvård/medicin,sv,health
-Presenter,sv,shopping
+Barnomsorg,sv,children
 Kläder,sv,shopping
+Presenter,sv,shopping
+Skatter,sv,fees
 Allmänt,sv,other
-Barnomsorg,sv,other
 Utbildning,sv,other
-Försäkringar,sv,other
-Skatter,sv,other
 Livet - Övrigt,sv,other