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/store.go

@@ -0,0 +1,155 @@
+package store
+
+import (
+	"database/sql"
+	"errors"
+	"fmt"
+	"time"
+
+	_ "modernc.org/sqlite"
+)
+
+// ErrNotFound is returned when a requested entity does not exist.
+var ErrNotFound = errors.New("not found")
+
+// Store wraps the SQLite database connection and provides access to all query methods.
+type Store struct {
+	db *sql.DB
+}
+
+// New opens a SQLite database at the given path and runs auto-migration.
+func New(dbPath string) (*Store, error) {
+	db, err := sql.Open("sqlite", dbPath)
+	if err != nil {
+		return nil, fmt.Errorf("open database: %w", err)
+	}
+
+	// Enable WAL mode and foreign keys for better concurrency and referential integrity.
+	pragmas := []string{
+		"PRAGMA journal_mode=WAL",
+		"PRAGMA foreign_keys=ON",
+		"PRAGMA busy_timeout=5000",
+	}
+	for _, p := range pragmas {
+		if _, err := db.Exec(p); err != nil {
+			db.Close()
+			return nil, fmt.Errorf("exec pragma %q: %w", p, err)
+		}
+	}
+
+	s := &Store{db: db}
+	if err := s.migrate(); err != nil {
+		db.Close()
+		return nil, fmt.Errorf("migrate: %w", err)
+	}
+
+	return s, nil
+}
+
+// Close closes the underlying database connection.
+func (s *Store) Close() error {
+	return s.db.Close()
+}
+
+// migrate creates all tables if they do not already exist.
+func (s *Store) migrate() error {
+	_, err := s.db.Exec(schema)
+	return err
+}
+
+const schema = `
+CREATE TABLE IF NOT EXISTS projects (
+	id         TEXT PRIMARY KEY,
+	name       TEXT NOT NULL UNIQUE,
+	registry   TEXT NOT NULL DEFAULT '',
+	image      TEXT NOT NULL,
+	port       INTEGER NOT NULL DEFAULT 0,
+	healthcheck TEXT NOT NULL DEFAULT '',
+	env        TEXT NOT NULL DEFAULT '{}',
+	volumes    TEXT NOT NULL DEFAULT '{}',
+	created_at TEXT NOT NULL DEFAULT (datetime('now')),
+	updated_at TEXT NOT NULL DEFAULT (datetime('now'))
+);
+
+CREATE TABLE IF NOT EXISTS stages (
+	id            TEXT PRIMARY KEY,
+	project_id    TEXT NOT NULL REFERENCES projects(id) ON DELETE CASCADE,
+	name          TEXT NOT NULL,
+	tag_pattern   TEXT NOT NULL DEFAULT '*',
+	auto_deploy   INTEGER NOT NULL DEFAULT 0,
+	max_instances INTEGER NOT NULL DEFAULT 1,
+	confirm       INTEGER NOT NULL DEFAULT 0,
+	promote_from  TEXT NOT NULL DEFAULT '',
+	subdomain     TEXT NOT NULL DEFAULT '',
+	created_at    TEXT NOT NULL DEFAULT (datetime('now')),
+	updated_at    TEXT NOT NULL DEFAULT (datetime('now')),
+	UNIQUE(project_id, name)
+);
+
+CREATE TABLE IF NOT EXISTS registries (
+	id         TEXT PRIMARY KEY,
+	name       TEXT NOT NULL UNIQUE,
+	url        TEXT NOT NULL,
+	type       TEXT NOT NULL DEFAULT 'generic',
+	token      TEXT NOT NULL DEFAULT '',
+	created_at TEXT NOT NULL DEFAULT (datetime('now')),
+	updated_at TEXT NOT NULL DEFAULT (datetime('now'))
+);
+
+CREATE TABLE IF NOT EXISTS settings (
+	id                  INTEGER PRIMARY KEY CHECK (id = 1),
+	domain              TEXT NOT NULL DEFAULT '',
+	server_ip           TEXT NOT NULL DEFAULT '',
+	network             TEXT NOT NULL DEFAULT '',
+	subdomain_pattern   TEXT NOT NULL DEFAULT 'stage-{stage}-{project}',
+	notification_url    TEXT NOT NULL DEFAULT '',
+	npm_url             TEXT NOT NULL DEFAULT '',
+	npm_email           TEXT NOT NULL DEFAULT '',
+	npm_password        TEXT NOT NULL DEFAULT '',
+	webhook_secret      TEXT NOT NULL DEFAULT '',
+	polling_interval    TEXT NOT NULL DEFAULT '5m',
+	updated_at          TEXT NOT NULL DEFAULT (datetime('now'))
+);
+
+CREATE TABLE IF NOT EXISTS instances (
+	id            TEXT PRIMARY KEY,
+	stage_id      TEXT NOT NULL REFERENCES stages(id) ON DELETE CASCADE,
+	project_id    TEXT NOT NULL REFERENCES projects(id) ON DELETE CASCADE,
+	container_id  TEXT NOT NULL DEFAULT '',
+	image_tag     TEXT NOT NULL,
+	subdomain     TEXT NOT NULL DEFAULT '',
+	npm_proxy_id  INTEGER NOT NULL DEFAULT 0,
+	status        TEXT NOT NULL DEFAULT 'stopped',
+	port          INTEGER NOT NULL DEFAULT 0,
+	created_at    TEXT NOT NULL DEFAULT (datetime('now')),
+	updated_at    TEXT NOT NULL DEFAULT (datetime('now'))
+);
+
+CREATE TABLE IF NOT EXISTS deploys (
+	id          TEXT PRIMARY KEY,
+	project_id  TEXT NOT NULL REFERENCES projects(id) ON DELETE CASCADE,
+	stage_id    TEXT NOT NULL REFERENCES stages(id) ON DELETE CASCADE,
+	instance_id TEXT NOT NULL DEFAULT '',
+	image_tag   TEXT NOT NULL,
+	status      TEXT NOT NULL DEFAULT 'pending',
+	started_at  TEXT NOT NULL DEFAULT (datetime('now')),
+	finished_at TEXT NOT NULL DEFAULT '',
+	error       TEXT NOT NULL DEFAULT ''
+);
+
+CREATE TABLE IF NOT EXISTS deploy_logs (
+	id         INTEGER PRIMARY KEY AUTOINCREMENT,
+	deploy_id  TEXT NOT NULL REFERENCES deploys(id) ON DELETE CASCADE,
+	message    TEXT NOT NULL,
+	level      TEXT NOT NULL DEFAULT 'info',
+	created_at TEXT NOT NULL DEFAULT (datetime('now'))
+);
+
+-- Seed the settings row if it does not exist.
+INSERT OR IGNORE INTO settings (id) VALUES (1);
+`
+
+// now returns the current time formatted for SQLite storage.
+func now() string {
+	return time.Now().UTC().Format("2006-01-02 15:04:05")
+}