Make shopping items editable: tap to rename, move store/section, delete

Tapping an item outside shopping mode now opens an edit sheet. User-added items
can be renamed, moved between stores and sections, and deleted. PlanToEat items
show why they cannot be edited — the client is read-only, so presenting fields
that silently would not save is worse than saying so — and offer removal, which
marks them checked, the same mechanism shopping mode already uses.

This needed a store registry first. Stores previously existed only because some
item referenced them by name, with Trello's list names quietly acting as the
registry; removing Trello as a source made the gap visible. Without a registry
you cannot move an item into an empty store, and moving the last item out of a
store makes it vanish mid-edit. Migration 034 adds shopping_stores and
shopping_sections, seeded from the stores currently in use, and gives items a
section column — sections previously existed only as PlanToEat category
strings, so a user item could not be filed under one at all.

Registered stores and sections now appear in the list even when empty, which is
the whole point of the registry.

Two deliberate choices about destructive edges:
  * Renaming a store renames it and moves its items in one transaction. Items
    reference the store by name, so doing either alone orphans them.
  * Deleting a store or section keeps the items, moving them to Unassigned or
    clearing the section. Losing the list is far worse than re-filing an item.
  * An UPDATE matching no rows is an error, not a silent success, so a stale id
    cannot look like a saved edit.

Section options are rebuilt per store in the edit sheet rather than shipped as
one flat list, so a Costco item cannot be filed under a Safeway aisle.

18 new store tests, 11 handler tests.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018AwnALZL6bD4VBtATDVv3B

1 files changed, 65 insertions, 4 deletions

diff --git a/internal/store/shopping.go b/internal/store/shopping.go
index 40571ac..448a2be 100644
--- a/internal/store/shopping.go
+++ b/internal/store/shopping.go
@@ -1,24 +1,85 @@
 package store
 
-import "time"
+import (
+	"database/sql"
+	"errors"
+	"fmt"
+	"strings"
+	"time"
+)
 
 type UserShoppingItem struct {
 	ID        int64
 	Name      string
 	Store     string
+	Section   string
 	Checked   bool
 	CreatedAt time.Time
 }
 
 // SaveUserShoppingItem saves a new user shopping item
 func (s *Store) SaveUserShoppingItem(name, store string) error {
-	_, err := s.db.Exec(`INSERT INTO user_shopping_items (name, store) VALUES (?, ?)`, name, store)
+	return s.SaveUserShoppingItemInSection(name, store, "")
+}
+
+// SaveUserShoppingItemInSection saves a new item filed under a section.
+func (s *Store) SaveUserShoppingItemInSection(name, store, section string) error {
+	_, err := s.db.Exec(
+		`INSERT INTO user_shopping_items (name, store, section) VALUES (?, ?, ?)`,
+		strings.TrimSpace(name), strings.TrimSpace(store), strings.TrimSpace(section))
 	return err
 }
 
+// UpdateUserShoppingItem renames an item and/or moves it between stores and
+// sections. Everything an edit can change goes through here, so a partial
+// update cannot leave an item half-moved.
+func (s *Store) UpdateUserShoppingItem(id int64, name, store, section string) error {
+	name = strings.TrimSpace(name)
+	store = strings.TrimSpace(store)
+	section = strings.TrimSpace(section)
+	if name == "" {
+		return fmt.Errorf("item name is required")
+	}
+	if store == "" {
+		return fmt.Errorf("store is required")
+	}
+
+	res, err := s.db.Exec(
+		`UPDATE user_shopping_items SET name = ?, store = ?, section = ? WHERE id = ?`,
+		name, store, section, id)
+	if err != nil {
+		return err
+	}
+	// An UPDATE that matches nothing succeeds at the SQL level, so a stale or
+	// wrong id would otherwise look like a successful edit.
+	if n, err := res.RowsAffected(); err == nil && n == 0 {
+		return ErrItemNotFound
+	}
+	return nil
+}
+
+// GetUserShoppingItem returns a single item, or ErrItemNotFound.
+func (s *Store) GetUserShoppingItem(id int64) (*UserShoppingItem, error) {
+	var item UserShoppingItem
+	err := s.db.QueryRow(
+		`SELECT id, name, store, COALESCE(section, ''), checked, created_at
+		 FROM user_shopping_items WHERE id = ?`, id).
+		Scan(&item.ID, &item.Name, &item.Store, &item.Section, &item.Checked, &item.CreatedAt)
+	if errors.Is(err, sql.ErrNoRows) {
+		return nil, ErrItemNotFound
+	}
+	if err != nil {
+		return nil, err
+	}
+	return &item, nil
+}
+
+// ErrItemNotFound is returned when an item id matches nothing.
+var ErrItemNotFound = errors.New("shopping item not found")
+
 // GetUserShoppingItems retrieves all user shopping items
 func (s *Store) GetUserShoppingItems() ([]UserShoppingItem, error) {
-	rows, err := s.db.Query(`SELECT id, name, store, checked, created_at FROM user_shopping_items ORDER BY store, created_at DESC`)
+	rows, err := s.db.Query(`SELECT id, name, store, COALESCE(section, ''), checked, created_at FROM user_shopping_items ORDER BY store, created_at DESC`)
 	if err != nil {
 		return nil, err
 	}
@@ -27,7 +88,7 @@ func (s *Store) GetUserShoppingItems() ([]UserShoppingItem, error) {
 	var items []UserShoppingItem
 	for rows.Next() {
 		var item UserShoppingItem
-		if err := rows.Scan(&item.ID, &item.Name, &item.Store, &item.Checked, &item.CreatedAt); err != nil {
+		if err := rows.Scan(&item.ID, &item.Name, &item.Store, &item.Section, &item.Checked, &item.CreatedAt); err != nil {
 			return nil, err
 		}
 		items = append(items, item)