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/projects.go

@@ -0,0 +1,95 @@
+package store
+
+import (
+	"database/sql"
+	"errors"
+	"fmt"
+
+	"github.com/google/uuid"
+)
+
+// CreateProject inserts a new project and returns it.
+func (s *Store) CreateProject(p Project) (Project, error) {
+	p.ID = uuid.New().String()
+	p.CreatedAt = now()
+	p.UpdatedAt = p.CreatedAt
+
+	_, err := s.db.Exec(
+		`INSERT INTO projects (id, name, registry, image, port, healthcheck, env, volumes, created_at, updated_at)
+		 VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`,
+		p.ID, p.Name, p.Registry, p.Image, p.Port, p.Healthcheck, p.Env, p.Volumes, p.CreatedAt, p.UpdatedAt,
+	)
+	if err != nil {
+		return Project{}, fmt.Errorf("insert project: %w", err)
+	}
+	return p, nil
+}
+
+// GetProjectByID returns a single project by its ID.
+func (s *Store) GetProjectByID(id string) (Project, error) {
+	var p Project
+	err := s.db.QueryRow(
+		`SELECT id, name, registry, image, port, healthcheck, env, volumes, created_at, updated_at
+		 FROM projects WHERE id = ?`, id,
+	).Scan(&p.ID, &p.Name, &p.Registry, &p.Image, &p.Port, &p.Healthcheck, &p.Env, &p.Volumes, &p.CreatedAt, &p.UpdatedAt)
+	if errors.Is(err, sql.ErrNoRows) {
+		return Project{}, fmt.Errorf("project %s: %w", id, ErrNotFound)
+	}
+	if err != nil {
+		return Project{}, fmt.Errorf("query project: %w", err)
+	}
+	return p, nil
+}
+
+// GetAllProjects returns every project ordered by name.
+func (s *Store) GetAllProjects() ([]Project, error) {
+	rows, err := s.db.Query(
+		`SELECT id, name, registry, image, port, healthcheck, env, volumes, created_at, updated_at
+		 FROM projects ORDER BY name`,
+	)
+	if err != nil {
+		return nil, fmt.Errorf("query projects: %w", err)
+	}
+	defer rows.Close()
+
+	var projects []Project
+	for rows.Next() {
+		var p Project
+		if err := rows.Scan(&p.ID, &p.Name, &p.Registry, &p.Image, &p.Port, &p.Healthcheck, &p.Env, &p.Volumes, &p.CreatedAt, &p.UpdatedAt); err != nil {
+			return nil, fmt.Errorf("scan project: %w", err)
+		}
+		projects = append(projects, p)
+	}
+	return projects, rows.Err()
+}
+
+// UpdateProject updates an existing project's mutable fields.
+func (s *Store) UpdateProject(p Project) error {
+	p.UpdatedAt = now()
+	result, err := s.db.Exec(
+		`UPDATE projects SET name=?, registry=?, image=?, port=?, healthcheck=?, env=?, volumes=?, updated_at=?
+		 WHERE id=?`,
+		p.Name, p.Registry, p.Image, p.Port, p.Healthcheck, p.Env, p.Volumes, p.UpdatedAt, p.ID,
+	)
+	if err != nil {
+		return fmt.Errorf("update project: %w", err)
+	}
+	n, _ := result.RowsAffected()
+	if n == 0 {
+		return fmt.Errorf("project %s: %w", p.ID, ErrNotFound)
+	}
+	return nil
+}
+
+// DeleteProject removes a project by ID. Cascading deletes handle stages, instances, and deploys.
+func (s *Store) DeleteProject(id string) error {
+	result, err := s.db.Exec(`DELETE FROM projects WHERE id = ?`, id)
+	if err != nil {
+		return fmt.Errorf("delete project: %w", err)
+	}
+	n, _ := result.RowsAffected()
+	if n == 0 {
+		return fmt.Errorf("project %s: %w", id, ErrNotFound)
+	}
+	return nil
+}