M12c: category contract v2 on Android (14 defaults, suggestCategory)

- :core:model: DefaultCategoryKey in AC-7.2 order (14 keys: housing, insurance, children, fees added),
  ColorToken + SLATE, AMBER, CategoryIcons.ALL + key, shield, account_balance (33),
  ExpenseRepository.suggestCategory(accountId, description); ContractTest updated.
- :domain: parseCategoryKeywords (pure, shared by :data and :core:fakes) with a parser test; the
  suggestCategory records and rule unchanged, suggest_category vectors pass.
- :data: PlatformUnicodeText (java.text.Normalizer, Character), CategoryKeywords parsed once from the
  Java resource that copyCategoryKeywords copies from contracts/category-keywords.csv at build time
  (missing file fails the build), ExpenseRepositoryImpl.suggestCategory over the Room snapshot and the
  DataStore last-used category; tests: byte identity and the 14.8 rules of the bundled table, the
  UnicodeText binding, and Room/Robolectric cases for history, first token, ties, keywords, fallback,
  archived categories, deleted expenses, both users and accounts, null account.
- :core:fakes: the 14 defaults with the schema v2 ids, fake suggestCategory through :domain with its own
  build-time copy of the table; tests.
- Room schema unchanged (version 1).

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

android/data/src/main/kotlin/se/hagstedt/kvitt/data/di/DataModule.kt

@@ -41,6 +41,7 @@ import se.hagstedt.kvitt.data.db.KvittDatabase
 import se.hagstedt.kvitt.data.repo.AboutRepositoryImpl
 import se.hagstedt.kvitt.data.repo.AccountRepositoryImpl
 import se.hagstedt.kvitt.data.repo.AnalyticsRepositoryImpl
+import se.hagstedt.kvitt.data.repo.CategoryKeywords
 import se.hagstedt.kvitt.data.repo.CategoryRepositoryImpl
 import se.hagstedt.kvitt.data.repo.DeviceRepositoryImpl
 import se.hagstedt.kvitt.data.repo.ExpenseRepositoryImpl
@@ -229,8 +230,18 @@ object DataModule {
         AccountRepositoryImpl(local, api, gate, db, clock)
 
     @Provides @Singleton
-    fun expenses(local: LocalData, db: KvittDatabase, prefs: PhonePrefs, clock: Clock, ids: IdGenerator, triggers: SyncTriggers): ExpenseRepositoryImpl =
-        ExpenseRepositoryImpl(local, db, prefs, clock, ids, triggers)
+    fun categoryKeywords(): CategoryKeywords = CategoryKeywords()
+
+    @Provides @Singleton
+    fun expenses(
+        local: LocalData,
+        db: KvittDatabase,
+        prefs: PhonePrefs,
+        clock: Clock,
+        ids: IdGenerator,
+        triggers: SyncTriggers,
+        keywords: CategoryKeywords,
+    ): ExpenseRepositoryImpl = ExpenseRepositoryImpl(local, db, prefs, clock, ids, triggers, keywords)
 
     @Provides @Singleton
     fun settlements(local: LocalData, db: KvittDatabase, clock: Clock, ids: IdGenerator, triggers: SyncTriggers): SettlementRepositoryImpl =

android/data/src/main/kotlin/se/hagstedt/kvitt/data/repo/CategorySuggestions.kt

@@ -0,0 +1,65 @@
+package se.hagstedt.kvitt.data.repo
+
+import kotlinx.datetime.LocalDate
+import se.hagstedt.kvitt.domain.ActiveCategory
+import se.hagstedt.kvitt.domain.CategoryKeyword
+import se.hagstedt.kvitt.domain.SuggestionHistoryEntry
+import se.hagstedt.kvitt.domain.UnicodeText
+import se.hagstedt.kvitt.domain.parseCategoryKeywords
+import se.hagstedt.kvitt.domain.suggestCategory
+import se.hagstedt.kvitt.model.AccountId
+import se.hagstedt.kvitt.model.CategoryId
+import java.text.Normalizer
+
+/** The platform's Unicode services for CS-4 (NFC, general categories). */
+object PlatformUnicodeText : UnicodeText {
+    override fun nfc(text: String): String = Normalizer.normalize(text, Normalizer.Form.NFC)
+
+    override fun isLetter(codePoint: Int): Boolean = Character.isLetter(codePoint)
+
+    override fun isDigit(codePoint: Int): Boolean = Character.getType(codePoint) == Character.DECIMAL_DIGIT_NUMBER.toInt()
+}
+
+/**
+ * The keyword table of CS-6: the Java resource [RESOURCE], copied from contracts/category-keywords.csv at build time
+ * by `:data:copyCategoryKeywords`, parsed once on first use.
+ */
+class CategoryKeywords(private val source: () -> String = ::bundledTable) {
+    val entries: List<CategoryKeyword> by lazy { parseCategoryKeywords(source()) }
+
+    companion object {
+        const val RESOURCE = "/se/hagstedt/kvitt/data/category-keywords.csv"
+
+        /** The bundled table as text (UTF-8). */
+        fun bundledTable(): String = checkNotNull(CategoryKeywords::class.java.getResourceAsStream(RESOURCE)) {
+            "category keyword table $RESOURCE is not on the class path"
+        }.use { it.readBytes().decodeToString() }
+    }
+}
+
+/**
+ * UX-3 over one snapshot: history is every non-deleted expense on the phone (all accounts, both users, pending ones
+ * included), active categories are the ones neither archived nor deleted, and the fallback is the AC-8.6 default for
+ * [accountId] ([lastCategoryFor] if still active, else `other`; `other` when no account is selected).
+ */
+internal fun Snapshot.suggestCategory(
+    accountId: AccountId?,
+    description: String,
+    lastCategoryFor: Map<String, String>,
+    keywords: List<CategoryKeyword>,
+): CategoryId? {
+    val active = categoryRows.filter { it.archivedAt == null && it.deletedAt == null }
+    val activeIds = active.map { it.id }.toSet()
+    val last = accountId?.let { lastCategoryFor[it.value] }?.takeIf { it in activeIds }
+    val fallback = (last ?: active.firstOrNull { it.defaultKey == OTHER_KEY }?.id)?.let { CategoryId(it) }
+    return suggestCategory(
+        description = description,
+        history = liveExpenses.map { SuggestionHistoryEntry(it.row.description, CategoryId(it.row.categoryId), LocalDate.parse(it.row.expenseDate), it.row.createdAt) },
+        keywords = keywords,
+        activeCategories = active.map { ActiveCategory(CategoryId(it.id), it.defaultKey) },
+        fallback = fallback,
+        unicode = PlatformUnicodeText,
+    )
+}
+
+private const val OTHER_KEY = "other"

android/data/src/main/kotlin/se/hagstedt/kvitt/data/repo/ExpenseRepositoryImpl.kt

@@ -21,6 +21,8 @@ import se.hagstedt.kvitt.data.util.nowTimestamp
 import se.hagstedt.kvitt.data.util.today
 import se.hagstedt.kvitt.domain.BP_TOTAL
 import se.hagstedt.kvitt.domain.computeSplit
+import se.hagstedt.kvitt.model.AccountId
+import se.hagstedt.kvitt.model.CategoryId
 import se.hagstedt.kvitt.model.DefaultCategoryKey
 import se.hagstedt.kvitt.model.ExpenseDetailState
 import se.hagstedt.kvitt.model.ExpenseDraft
@@ -44,6 +46,7 @@ class ExpenseRepositoryImpl(
     private val clock: Clock,
     private val ids: IdGenerator,
     private val writes: LocalWriteListener,
+    private val keywords: CategoryKeywords,
 ) : ExpenseRepository {
     private val timelines = Timelines(db, local)
 
@@ -73,8 +76,8 @@ class ExpenseRepositoryImpl(
         val e = local.snapshot.first().expense(id.value)?.takeIf { !it.deleted } ?: return null
         return ExpenseDraft(
             id = e.id,
-            accountId = se.hagstedt.kvitt.model.AccountId(e.row.accountId),
-            categoryId = se.hagstedt.kvitt.model.CategoryId(e.row.categoryId),
+            accountId = AccountId(e.row.accountId),
+            categoryId = CategoryId(e.row.categoryId),
             amountOre = e.row.amountOre,
             description = e.row.description,
             notes = e.row.notes,
@@ -181,6 +184,10 @@ class ExpenseRepositoryImpl(
         )
     }.distinctUntilChanged()
 
+    /** UX-3 (CS-5): a local computation over the Room snapshot and the bundled keyword table; no network (CS-3). */
+    override suspend fun suggestCategory(accountId: AccountId?, description: String): CategoryId? =
+        local.snapshot.first().suggestCategory(accountId, description, prefs.editorDefaults.first().lastCategoryFor, keywords.entries)
+
     companion object {
         const val REQUIRED = "required"