M9: kvitt-import Splitwise importer (SPEC §10.8, FR-17)

CLI per §10.8 with --help, --dry-run and a summary; English and Swedish
headers with member columns matched by name; CSV quoting; payments as
settlements with one allocation; trailing totals row used to reconcile
the account balance (mismatch rolls back, exit 4); non-SEK rows abort
unless --fx; committed category table data/splitwise_categories.csv;
idempotent re-runs through import_key; rows validated with the server's
push checks, audited with source import, no pushes; one BEGIN IMMEDIATE
transaction. Tests over synthetic fixtures only.

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

server/crates/kvitt-import/tests/fixtures/bad_header.csv

@@ -0,0 +1,2 @@
+Date,Description,Category,Amount,Currency,Alex Example,Robin Sample
+2025-05-01,Fine row,Groceries,10.00,SEK,5.00,-5.00

server/crates/kvitt-import/tests/fixtures/english.csv

@@ -0,0 +1,15 @@
+Date,Description,Category,Cost,Currency,Alex Example,Robin Sample
+
+2025-01-05,Weekly shop,Groceries,300.00,SEK,150.00,-150.00
+2025-01-06,"Paint, brushes and tape",Household supplies,120.50,SEK,-60.25,60.25
+2025-01-07,Cinema,Movies,200.00,SEK,0.00,0.00
+2025-01-08,Bus card,Bus/train,100.00,SEK,-100.00,100.00
+2025-01-09,Mystery box,Widgets,50.00,SEK,25.00,-25.00
+2025-01-10,Coffee,Dining out,40.00,SEK,20.00,-20.00
+2025-01-10,Coffee,Dining out,40.00,SEK,20.00,-20.00
+2025-01-11,An extremely long synthetic description written only to exercise the truncation rule of the importer at one hundred code points,General,10.00,SEK,5.00,-5.00
+2025-01-12,Robin paid Alex,Payment,100.00,SEK,-100.00,100.00
+2025-01-13,"Rent, January",Rent,1000.00,SEK,500.00,-500.00
+
+2025-01-14,Total balance, , ,SEK,459.75,-459.75
+

server/crates/kvitt-import/tests/fixtures/invalid_date.csv

@@ -0,0 +1,7 @@
+Date,Description,Category,Cost,Currency,Alex Example,Robin Sample
+
+2025-04-01,Fine row,Groceries,10.00,SEK,5.00,-5.00
+2025-13-01,Bad date,Groceries,10.00,SEK,5.00,-5.00
+
+2025-04-03,Total balance, , ,SEK,10.00,-10.00
+

server/crates/kvitt-import/tests/fixtures/invalid_nets.csv

@@ -0,0 +1,7 @@
+Date,Description,Category,Cost,Currency,Alex Example,Robin Sample
+
+2025-04-01,Fine row,Groceries,10.00,SEK,5.00,-5.00
+2025-04-02,Broken row,Groceries,10.00,SEK,5.00,-4.00
+
+2025-04-03,Total balance, , ,SEK,10.00,-9.00
+

server/crates/kvitt-import/tests/fixtures/mismatch.csv

@@ -0,0 +1,6 @@
+Date,Description,Category,Cost,Currency,Alex Example,Robin Sample
+
+2025-05-01,Fine row,Groceries,10.00,SEK,5.00,-5.00
+
+2025-05-02,Total balance, , ,SEK,7.00,-7.00
+

server/crates/kvitt-import/tests/fixtures/no_totals.csv

@@ -0,0 +1,2 @@
+Date,Description,Category,Cost,Currency,Alex Example,Robin Sample
+2025-05-01,Fine row,Groceries,10.00,SEK,5.00,-5.00

server/crates/kvitt-import/tests/fixtures/non_sek.csv

@@ -0,0 +1,8 @@
+Date,Description,Category,Cost,Currency,Alex Example,Robin Sample
+
+2025-03-01,Market,Groceries,100.00,SEK,50.00,-50.00
+2025-03-02,Hotel abroad,Hotel,10.00,EUR,5.00,-5.00
+
+2025-03-03,Total balance, , ,SEK,50.00,-50.00
+2025-03-03,Total balance, , ,EUR,5.00,-5.00
+

server/crates/kvitt-import/tests/fixtures/swedish.csv

@@ -0,0 +1,10 @@
+Datum,Beskrivning,Kategori,Kostnad,Valuta,Robin Sample,Alex Example
+
+2025-02-01,Matkasse,Livsmedel,200.00,SEK,-100.00,100.00
+2025-02-02,"Lampa, golv",Möbler,80.00,SEK,40.00,-40.00
+2025-02-03,Okänd sak,Påhittad kategori,10.00,SEK,5.00,-5.00
+2025-02-04,Betalning till Alex,Betalning,55.00,SEK,55.00,-55.00
+2025-02-05,Biljett,Buss/tåg,30.00,SEK,-15.00,15.00
+
+2025-02-06,Totalsumma, , ,SEK,-15.00,15.00
+

server/crates/kvitt-import/tests/fixtures/wrong_member.csv

@@ -0,0 +1,4 @@
+Date,Description,Category,Cost,Currency,Alex Example,Sam Other
+2025-05-01,Fine row,Groceries,10.00,SEK,5.00,-5.00
+
+2025-05-02,Total balance, , ,SEK,5.00,-5.00