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/config/config.go

@@ -0,0 +1,97 @@
+// Package config loads smartrund's runtime configuration from environment
+// variables (a single-user local app has no need for a config file/flags
+// beyond this).
+package config
+
+import (
+	"fmt"
+	"os"
+	"strconv"
+	"time"
+)
+
+// Config holds everything smartrund needs to start.
+type Config struct {
+	// Addr is the HTTP listen address, e.g. ":8080".
+	Addr string
+	// DBPath is the SQLite database file path.
+	DBPath string
+
+	// GarminPythonPath is mcp-garmin's venv python executable.
+	GarminPythonPath string
+	// GarminServerPath is mcp-garmin's server.py.
+	GarminServerPath string
+	GarminEmail      string
+	GarminPassword   string
+	// GarminTokenStore, if set, overrides mcp-garmin's default ~/.garth
+	// session cache location.
+	GarminTokenStore string
+
+	MaxHR                float64
+	MinConfidence        float64
+	BackfillHorizonDays  int
+	IncrementalSyncEvery time.Duration
+}
+
+// Load reads configuration from environment variables, applying defaults
+// for anything optional. Returns an error if a required variable is unset.
+func Load() (Config, error) {
+	cfg := Config{
+		Addr:                 getEnvDefault("SMARTRUN_ADDR", ":8080"),
+		DBPath:               getEnvDefault("SMARTRUN_DB_PATH", "smartrun.db"),
+		GarminPythonPath:     os.Getenv("MCP_GARMIN_PYTHON"),
+		GarminServerPath:     os.Getenv("MCP_GARMIN_SERVER"),
+		GarminEmail:          os.Getenv("GARMIN_EMAIL"),
+		GarminPassword:       os.Getenv("GARMIN_PASSWORD"),
+		GarminTokenStore:     os.Getenv("GARMIN_TOKENSTORE"),
+		MaxHR:                getEnvFloat("SMARTRUN_MAX_HR", 190),
+		MinConfidence:        getEnvFloat("SMARTRUN_MIN_CONFIDENCE", 0.6),
+		BackfillHorizonDays:  getEnvInt("SMARTRUN_BACKFILL_HORIZON_DAYS", 3*365),
+		IncrementalSyncEvery: getEnvDuration("SMARTRUN_INCREMENTAL_SYNC_EVERY", 6*time.Hour),
+	}
+
+	if cfg.GarminPythonPath == "" {
+		return cfg, fmt.Errorf("MCP_GARMIN_PYTHON is required (path to mcp-garmin's venv python)")
+	}
+	if cfg.GarminServerPath == "" {
+		return cfg, fmt.Errorf("MCP_GARMIN_SERVER is required (path to mcp-garmin's server.py)")
+	}
+	if cfg.GarminEmail == "" || cfg.GarminPassword == "" {
+		return cfg, fmt.Errorf("GARMIN_EMAIL and GARMIN_PASSWORD are required")
+	}
+	return cfg, nil
+}
+
+func getEnvDefault(key, def string) string {
+	if v := os.Getenv(key); v != "" {
+		return v
+	}
+	return def
+}
+
+func getEnvFloat(key string, def float64) float64 {
+	if v := os.Getenv(key); v != "" {
+		if f, err := strconv.ParseFloat(v, 64); err == nil {
+			return f
+		}
+	}
+	return def
+}
+
+func getEnvInt(key string, def int) int {
+	if v := os.Getenv(key); v != "" {
+		if n, err := strconv.Atoi(v); err == nil {
+			return n
+		}
+	}
+	return def
+}
+
+func getEnvDuration(key string, def time.Duration) time.Duration {
+	if v := os.Getenv(key); v != "" {
+		if d, err := time.ParseDuration(v); err == nil {
+			return d
+		}
+	}
+	return def
+}