Initial commit: DreamDict HTTP dictionary service

Go-based dictionary backend providing word validation, definitions, synonyms,
and cross-language translation for English, French, and Portuguese. Designed
as a self-hosted replacement for Wordnik, backing GogoBee.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

internal/dictionary/dict.go

@@ -0,0 +1,93 @@
+package dictionary
+
+import (
+	"database/sql"
+	"errors"
+)
+
+var (
+	ErrNoMatch   = errors.New("dictionary: no word matches filters")
+	ErrNotSeeded = errors.New("dictionary: database not seeded, run: go run ./cmd/dictimport")
+)
+
+var supportedLangs = []string{"en", "fr", "pt-PT"}
+
+func ValidLang(lang string) bool {
+	for _, l := range supportedLangs {
+		if l == lang {
+			return true
+		}
+	}
+	return false
+}
+
+type Options struct {
+	MinLength    int
+	MaxLength    int
+	POS          string // "", "noun", "verb", "adjective", "adverb"
+	MinFrequency int    // 0 = no filter
+}
+
+type Definition struct {
+	POS      string `json:"pos"`
+	Gloss    string `json:"gloss"`
+	Source   string `json:"source"`
+	Priority int    `json:"priority"`
+}
+
+type Dictionary struct {
+	db *sql.DB
+}
+
+// New opens the database read-write (for import CLI).
+func New(dbPath string) (*Dictionary, error) {
+	db, err := openDB(dbPath)
+	if err != nil {
+		return nil, err
+	}
+	d := &Dictionary{db: db}
+	if err := d.checkSeeded(); err != nil {
+		db.Close()
+		return nil, err
+	}
+	return d, nil
+}
+
+// NewReadOnly opens the database read-only with concurrent read support (for server).
+func NewReadOnly(dbPath string) (*Dictionary, error) {
+	db, err := openReadOnlyDB(dbPath)
+	if err != nil {
+		return nil, err
+	}
+	d := &Dictionary{db: db}
+	if err := d.checkSeeded(); err != nil {
+		db.Close()
+		return nil, err
+	}
+	return d, nil
+}
+
+// NewFromDB creates a Dictionary from an existing *sql.DB (useful for testing).
+func NewFromDB(db *sql.DB) *Dictionary {
+	return &Dictionary{db: db}
+}
+
+func (d *Dictionary) Close() error {
+	return d.db.Close()
+}
+
+func (d *Dictionary) checkSeeded() error {
+	var count int
+	err := d.db.QueryRow("SELECT COUNT(*) FROM meta").Scan(&count)
+	if err != nil {
+		return ErrNotSeeded
+	}
+	if count == 0 {
+		return ErrNotSeeded
+	}
+	return nil
+}
+
+func (d *Dictionary) SupportedLangs() []string {
+	return supportedLangs
+}