feat(docker-watcher): phase 1 - project scaffold & SQLite store

Initialize Go module, directory structure, and full SQLite store layer:
- 7-table schema (projects, stages, registries, settings, instances,
  deploys, deploy_logs) with auto-migration
- CRUD operations for all entities with proper error handling
- ErrNotFound sentinel for distinguishing 404 from 500 in handlers
- WAL mode, foreign keys, busy timeout pragmas

internal/store/registries.go

@@ -0,0 +1,95 @@
+package store
+
+import (
+	"database/sql"
+	"errors"
+	"fmt"
+
+	"github.com/google/uuid"
+)
+
+// CreateRegistry inserts a new registry.
+func (s *Store) CreateRegistry(r Registry) (Registry, error) {
+	r.ID = uuid.New().String()
+	r.CreatedAt = now()
+	r.UpdatedAt = r.CreatedAt
+
+	_, err := s.db.Exec(
+		`INSERT INTO registries (id, name, url, type, token, created_at, updated_at)
+		 VALUES (?, ?, ?, ?, ?, ?, ?)`,
+		r.ID, r.Name, r.URL, r.Type, r.Token, r.CreatedAt, r.UpdatedAt,
+	)
+	if err != nil {
+		return Registry{}, fmt.Errorf("insert registry: %w", err)
+	}
+	return r, nil
+}
+
+// GetRegistryByID returns a single registry by its ID.
+func (s *Store) GetRegistryByID(id string) (Registry, error) {
+	var r Registry
+	err := s.db.QueryRow(
+		`SELECT id, name, url, type, token, created_at, updated_at
+		 FROM registries WHERE id = ?`, id,
+	).Scan(&r.ID, &r.Name, &r.URL, &r.Type, &r.Token, &r.CreatedAt, &r.UpdatedAt)
+	if errors.Is(err, sql.ErrNoRows) {
+		return Registry{}, fmt.Errorf("registry %s: %w", id, ErrNotFound)
+	}
+	if err != nil {
+		return Registry{}, fmt.Errorf("query registry: %w", err)
+	}
+	return r, nil
+}
+
+// GetAllRegistries returns every registry ordered by name.
+func (s *Store) GetAllRegistries() ([]Registry, error) {
+	rows, err := s.db.Query(
+		`SELECT id, name, url, type, token, created_at, updated_at
+		 FROM registries ORDER BY name`,
+	)
+	if err != nil {
+		return nil, fmt.Errorf("query registries: %w", err)
+	}
+	defer rows.Close()
+
+	var registries []Registry
+	for rows.Next() {
+		var r Registry
+		if err := rows.Scan(&r.ID, &r.Name, &r.URL, &r.Type, &r.Token, &r.CreatedAt, &r.UpdatedAt); err != nil {
+			return nil, fmt.Errorf("scan registry: %w", err)
+		}
+		registries = append(registries, r)
+	}
+	return registries, rows.Err()
+}
+
+// UpdateRegistry updates an existing registry's mutable fields.
+func (s *Store) UpdateRegistry(r Registry) error {
+	r.UpdatedAt = now()
+	result, err := s.db.Exec(
+		`UPDATE registries SET name=?, url=?, type=?, token=?, updated_at=?
+		 WHERE id=?`,
+		r.Name, r.URL, r.Type, r.Token, r.UpdatedAt, r.ID,
+	)
+	if err != nil {
+		return fmt.Errorf("update registry: %w", err)
+	}
+	n, _ := result.RowsAffected()
+	if n == 0 {
+		return fmt.Errorf("registry %s: %w", r.ID, ErrNotFound)
+	}
+	return nil
+}
+
+// DeleteRegistry removes a registry by ID.
+func (s *Store) DeleteRegistry(id string) error {
+	result, err := s.db.Exec(`DELETE FROM registries WHERE id = ?`, id)
+	if err != nil {
+		return fmt.Errorf("delete registry: %w", err)
+	}
+	n, _ := result.RowsAffected()
+	if n == 0 {
+		return fmt.Errorf("registry %s: %w", id, ErrNotFound)
+	}
+	return nil
+}