Initial commit: smartrun MVP

Garmin run classification and progression tracker. Go backend (MCP
client to mcp-garmin, SQLite store, deterministic rule engine, REST
API) and React/TS frontend (Dashboard, Review Queue, Workout Kinds).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

backend/internal/store/db.go

@@ -0,0 +1,98 @@
+// Package store is smartrun's SQLite persistence layer: activities, laps,
+// per-second samples, workout kind rule config, and classification history.
+package store
+
+import (
+	"database/sql"
+	"embed"
+	"fmt"
+	"io/fs"
+	"sort"
+
+	_ "modernc.org/sqlite"
+)
+
+//go:embed migrations/*.sql
+var migrationsFS embed.FS
+
+// DB wraps a *sql.DB opened against a smartrun SQLite database file, with
+// migrations already applied.
+type DB struct {
+	*sql.DB
+}
+
+// Open opens (creating if needed) the SQLite database at path and applies
+// any migrations that haven't run yet.
+func Open(path string) (*DB, error) {
+	sqlDB, err := sql.Open("sqlite", path+"?_pragma=foreign_keys(1)")
+	if err != nil {
+		return nil, fmt.Errorf("open sqlite database: %w", err)
+	}
+	// SQLite only supports one writer at a time; a single connection avoids
+	// "database is locked" errors under any concurrent access from the app.
+	sqlDB.SetMaxOpenConns(1)
+
+	db := &DB{DB: sqlDB}
+	if err := db.migrate(); err != nil {
+		sqlDB.Close()
+		return nil, err
+	}
+	return db, nil
+}
+
+func (db *DB) migrate() error {
+	if _, err := db.Exec(`CREATE TABLE IF NOT EXISTS schema_migrations (
+		filename TEXT PRIMARY KEY,
+		applied_at TEXT NOT NULL DEFAULT (datetime('now'))
+	)`); err != nil {
+		return fmt.Errorf("create schema_migrations table: %w", err)
+	}
+
+	applied := make(map[string]bool)
+	rows, err := db.Query(`SELECT filename FROM schema_migrations`)
+	if err != nil {
+		return fmt.Errorf("query applied migrations: %w", err)
+	}
+	for rows.Next() {
+		var name string
+		if err := rows.Scan(&name); err != nil {
+			rows.Close()
+			return fmt.Errorf("scan applied migration: %w", err)
+		}
+		applied[name] = true
+	}
+	rows.Close()
+
+	entries, err := fs.Glob(migrationsFS, "migrations/*.sql")
+	if err != nil {
+		return fmt.Errorf("glob migrations: %w", err)
+	}
+	sort.Strings(entries)
+
+	for _, entry := range entries {
+		name := entry[len("migrations/"):]
+		if applied[name] {
+			continue
+		}
+		content, err := migrationsFS.ReadFile(entry)
+		if err != nil {
+			return fmt.Errorf("read migration %s: %w", name, err)
+		}
+		tx, err := db.Begin()
+		if err != nil {
+			return fmt.Errorf("begin migration tx for %s: %w", name, err)
+		}
+		if _, err := tx.Exec(string(content)); err != nil {
+			tx.Rollback()
+			return fmt.Errorf("apply migration %s: %w", name, err)
+		}
+		if _, err := tx.Exec(`INSERT INTO schema_migrations (filename) VALUES (?)`, name); err != nil {
+			tx.Rollback()
+			return fmt.Errorf("record migration %s: %w", name, err)
+		}
+		if err := tx.Commit(); err != nil {
+			return fmt.Errorf("commit migration %s: %w", name, err)
+		}
+	}
+	return nil
+}