feat: manage categories -- edit built-ins, add your own, backfill

CLAUDE.md

@@ -20,7 +20,7 @@ The reference deployment is live at https://finitum.app (Lightsail VPS, deployed
 - **Backend**: FastAPI (`src/api/server.py`), PostgreSQL + Alembic (`src/db/`, `alembic/`), Redis (dedupe + Gmail-confirmation capture).
 - **Ingestion**: `src/email_service/ingest.py` -- resolves user by `ingest_token` from the `u-<token>@<INGEST_DOMAIN>` recipient, HMAC-verifies `X-Finitum-Signature` (`INGEST_WEBHOOK_SECRET`), dedupes on `Message-ID`, auto-captures Gmail forwarding-confirmation links/codes into Redis for one-click setup. Worker lives in `infra/email-worker/`.
 - **Parsers**: fully data-driven. All bank logic lives in `src/parsers/regex.json` (per-bank: `remitents` sender allowlist, `subject` classification patterns, `body` extraction regexes). Engine: `src/parsers/parser.py` (`EmailParser`, `BankPatterns.from_json`). The bank is a per-user setting (`User.bank`); there is no content-based bank auto-detection. `GET /banks` derives the bank list from `regex.json` keys.
-- **Categories**: keyword matching in `src/parsers/base.py` from root `categories.json`; slugs/labels registry in `src/category_catalog.py`; Spanish overrides in `category_labels.es.json`; per-user custom categories via `POST /categories` + `src/db/categories.py`.
+- **Categories**: keyword matching in `src/parsers/base.py` from root `categories.json`; slugs/labels registry in `src/category_catalog.py`; Spanish overrides in `category_labels.es.json`. `categories.json` only seeds the shared catalog -- at runtime everything (including transference categorization) resolves through `src/db/categories.py` against the `categories` / `category_patterns` / `category_overrides` tables. Builtin categories are global rows, so a user editing one gets a private `CategoryOverride` (rename) plus forked `CategoryPattern` rows; `POST /categories/{id}/reset` drops both. `POST /categories/recategorize` re-applies keywords to stored expenses and transferences, leaving unmatched rows on their current category. UI lives at `web/app/routes/categories.tsx`.
 - **Frontend**: React Router v7 + TypeScript + Tailwind + Bun in `web/` (file routes under `web/app/routes/`). `profile.tsx` holds the up-to-date forwarding-setup UX; `home.tsx` and `guide.tsx` still carry stale OAuth-era messaging.
 
 ## Adding a bank (the core contributor flow)

alembic/versions/c4d7e1b9a250_add_user_category_overrides.py

@@ -0,0 +1,111 @@
+"""add per-user category overrides and pattern ownership
+
+Builtin categories are shared rows, so a user cannot edit them in place. This
+migration adds:
+
+* ``category_patterns.user_id`` -- NULL for the shared catalog rows, set when
+  the keyword belongs to a user (their own category, or their fork of a
+  builtin one).
+* ``category_overrides`` -- a user's rename of a builtin category and the flag
+  marking that they took over its keyword set.
+
+Revision ID: c4d7e1b9a250
+Revises: b3f1c2a4d5e6
+Create Date: 2026-07-25
+
+"""
+
+from collections.abc import Sequence
+
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision: str = "c4d7e1b9a250"
+down_revision: str | Sequence[str] | None = "b3f1c2a4d5e6"
+branch_labels: str | Sequence[str] | None = None
+depends_on: str | Sequence[str] | None = None
+
+LEGACY_PATTERN_INDEX = "ix_category_patterns_category_id_pattern"
+PATTERN_INDEX = "ix_category_patterns_category_id_user_id_pattern"
+
+
+def _index_names(table_name: str) -> set[str]:
+    inspector = sa.inspect(op.get_bind())
+    return {index["name"] for index in inspector.get_indexes(table_name)}
+
+
+def upgrade() -> None:
+    """Add pattern ownership and the per-user override table."""
+    op.add_column("category_patterns", sa.Column("user_id", sa.Integer(), nullable=True))
+    op.create_foreign_key(
+        "fk_category_patterns_user_id_users",
+        "category_patterns",
+        "users",
+        ["user_id"],
+        ["id"],
+    )
+    op.create_index("ix_category_patterns_user_id", "category_patterns", ["user_id"], unique=False)
+
+    # Keywords of a user-owned category belong to that user.
+    op.execute(
+        sa.text(
+            """
+            UPDATE category_patterns
+            SET user_id = (
+                SELECT categories.user_id
+                FROM categories
+                WHERE categories.id = category_patterns.category_id
+            )
+            """
+        )
+    )
+
+    # A forked keyword set repeats builtin keywords for the same category, so
+    # uniqueness has to include the owner.
+    if LEGACY_PATTERN_INDEX in _index_names("category_patterns"):
+        op.drop_index(LEGACY_PATTERN_INDEX, table_name="category_patterns")
+    op.create_index(
+        PATTERN_INDEX,
+        "category_patterns",
+        ["category_id", "user_id", "pattern"],
+        unique=True,
+    )
+
+    op.create_table(
+        "category_overrides",
+        sa.Column("id", sa.Integer(), nullable=False),
+        sa.Column("user_id", sa.Integer(), nullable=False),
+        sa.Column("category_id", sa.Integer(), nullable=False),
+        sa.Column("name", sa.String(), nullable=True),
+        sa.Column("patterns_overridden", sa.Boolean(), nullable=False, server_default=sa.false()),
+        sa.ForeignKeyConstraint(["user_id"], ["users.id"]),
+        sa.ForeignKeyConstraint(["category_id"], ["categories.id"]),
+        sa.PrimaryKeyConstraint("id"),
+        sa.UniqueConstraint("user_id", "category_id", name="uq_category_overrides_user_category"),
+    )
+    op.create_index("ix_category_overrides_user_id", "category_overrides", ["user_id"], unique=False)
+    op.create_index("ix_category_overrides_category_id", "category_overrides", ["category_id"], unique=False)
+
+
+def downgrade() -> None:
+    """Drop overrides and pattern ownership, keeping only the shared catalog."""
+    op.drop_index("ix_category_overrides_category_id", table_name="category_overrides")
+    op.drop_index("ix_category_overrides_user_id", table_name="category_overrides")
+    op.drop_table("category_overrides")
+
+    # Forked keywords have no home in the old schema.
+    op.execute(sa.text("DELETE FROM category_patterns WHERE user_id IS NOT NULL"))
+
+    if PATTERN_INDEX in _index_names("category_patterns"):
+        op.drop_index(PATTERN_INDEX, table_name="category_patterns")
+    op.drop_index("ix_category_patterns_user_id", table_name="category_patterns")
+    op.drop_constraint("fk_category_patterns_user_id_users", "category_patterns", type_="foreignkey")
+    op.drop_column("category_patterns", "user_id")
+    op.create_index(
+        LEGACY_PATTERN_INDEX,
+        "category_patterns",
+        ["category_id", "pattern"],
+        unique=True,
+    )

alembic/versions/d5b8f1c07e42_add_transference_category_id.py

@@ -0,0 +1,130 @@
+"""point transferences at the categories catalog
+
+Transferences stored their category as a builtin enum slug, so a user's own
+category could never apply to them. This mirrors what expenses already do:
+a ``category_id`` FK, backfilled from the legacy enum column.
+
+Revision ID: d5b8f1c07e42
+Revises: c4d7e1b9a250
+Create Date: 2026-07-25
+
+"""
+
+from collections.abc import Sequence
+
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects import postgresql
+
+
+# revision identifiers, used by Alembic.
+revision: str = "d5b8f1c07e42"
+down_revision: str | Sequence[str] | None = "c4d7e1b9a250"
+branch_labels: str | Sequence[str] | None = None
+depends_on: str | Sequence[str] | None = None
+
+GENERAL_CATEGORY_SLUG = "general"
+
+
+def _legacy_category_type() -> sa.types.TypeEngine:
+    """The pre-existing ``expensecategory`` enum, which is never dropped."""
+    if op.get_bind().dialect.name == "postgresql":
+        return postgresql.ENUM(name="expensecategory", create_type=False)
+    return sa.String()
+
+
+def _column_names(table_name: str) -> set[str]:
+    inspector = sa.inspect(op.get_bind())
+    return {column["name"] for column in inspector.get_columns(table_name)}
+
+
+def _global_categories_by_slug() -> dict[str, int]:
+    connection = op.get_bind()
+    metadata = sa.MetaData()
+    categories = sa.Table("categories", metadata, autoload_with=connection)
+    return {
+        row.slug: row.id
+        for row in connection.execute(
+            sa.select(categories.c.id, categories.c.slug).where(categories.c.user_id.is_(None))
+        )
+    }
+
+
+def _normalize_legacy_category(value: object | None) -> str:
+    if value is None:
+        return GENERAL_CATEGORY_SLUG
+    normalized = str(value).split(".")[-1].strip().lower()
+    return normalized or GENERAL_CATEGORY_SLUG
+
+
+def _backfill_transference_categories() -> None:
+    connection = op.get_bind()
+    metadata = sa.MetaData()
+    transferences = sa.Table("transferences", metadata, autoload_with=connection)
+
+    categories_by_slug = _global_categories_by_slug()
+    default_category_id = categories_by_slug[GENERAL_CATEGORY_SLUG]
+    has_legacy_column = "category" in _column_names("transferences")
+
+    if has_legacy_column:
+        rows = connection.execute(
+            sa.select(transferences.c.id, transferences.c.category, transferences.c.category_id)
+        ).all()
+    else:
+        rows = connection.execute(sa.select(transferences.c.id, transferences.c.category_id)).all()
+
+    for row in rows:
+        if row.category_id is not None:
+            continue
+        slug = _normalize_legacy_category(getattr(row, "category", None))
+        category_id = categories_by_slug.get(slug, default_category_id)
+        connection.execute(
+            transferences.update().where(transferences.c.id == row.id).values(category_id=category_id)
+        )
+
+
+def upgrade() -> None:
+    """Add transferences.category_id, backfilled from the legacy enum."""
+    if "category_id" not in _column_names("transferences"):
+        op.add_column("transferences", sa.Column("category_id", sa.Integer(), nullable=True))
+
+    _backfill_transference_categories()
+
+    with op.batch_alter_table("transferences") as batch_op:
+        batch_op.create_foreign_key(
+            "fk_transferences_category_id_categories", "categories", ["category_id"], ["id"]
+        )
+        batch_op.create_index("ix_transferences_category_id", ["category_id"], unique=False)
+        batch_op.alter_column("category_id", existing_type=sa.Integer(), nullable=False)
+        if "category" in _column_names("transferences"):
+            batch_op.drop_column("category")
+
+
+def downgrade() -> None:
+    """Restore the legacy enum column from the linked category slug."""
+    if "category" not in _column_names("transferences"):
+        op.add_column("transferences", sa.Column("category", _legacy_category_type(), nullable=True))
+
+    connection = op.get_bind()
+    metadata = sa.MetaData()
+    transferences = sa.Table("transferences", metadata, autoload_with=connection)
+    categories = sa.Table("categories", metadata, autoload_with=connection)
+
+    slugs_by_id = {row.id: row.slug for row in connection.execute(sa.select(categories.c.id, categories.c.slug))}
+    global_slugs = {
+        row.slug
+        for row in connection.execute(sa.select(categories.c.slug).where(categories.c.user_id.is_(None)))
+    }
+    for row in connection.execute(sa.select(transferences.c.id, transferences.c.category_id)):
+        # Custom categories have no enum member, so they fall back to general.
+        slug = slugs_by_id.get(row.category_id, GENERAL_CATEGORY_SLUG)
+        if slug not in global_slugs:
+            slug = GENERAL_CATEGORY_SLUG
+        connection.execute(
+            transferences.update().where(transferences.c.id == row.id).values(category=slug.upper())
+        )
+
+    with op.batch_alter_table("transferences") as batch_op:
+        batch_op.drop_index("ix_transferences_category_id")
+        batch_op.drop_constraint("fk_transferences_category_id_categories", type_="foreignkey")
+        batch_op.drop_column("category_id")