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/samples.go

@@ -0,0 +1,66 @@
+package store
+
+import (
+	"context"
+	"fmt"
+)
+
+// Sample is one ~1-second telemetry reading for an activity.
+type Sample struct {
+	ElapsedSeconds float64
+	TimestampMs    int64
+	HeartRate      *float64
+	SpeedMps       *float64
+	DistanceM      *float64
+	ElevationM     *float64
+}
+
+// ReplaceActivitySamples deletes any existing samples for activityID and
+// bulk-inserts the given set, so re-syncing an activity's details is idempotent.
+func (db *DB) ReplaceActivitySamples(ctx context.Context, activityID int64, samples []Sample) error {
+	tx, err := db.BeginTx(ctx, nil)
+	if err != nil {
+		return fmt.Errorf("begin replace samples tx: %w", err)
+	}
+	defer tx.Rollback()
+
+	if _, err := tx.ExecContext(ctx, `DELETE FROM activity_samples WHERE activity_id = ?`, activityID); err != nil {
+		return fmt.Errorf("delete existing samples for activity %d: %w", activityID, err)
+	}
+
+	stmt, err := tx.PrepareContext(ctx, `
+		INSERT INTO activity_samples (activity_id, elapsed_seconds, timestamp_ms, heart_rate, speed_mps, distance_m, elevation_m)
+		VALUES (?,?,?,?,?,?,?)`)
+	if err != nil {
+		return fmt.Errorf("prepare insert sample: %w", err)
+	}
+	defer stmt.Close()
+
+	for _, s := range samples {
+		if _, err := stmt.ExecContext(ctx, activityID, s.ElapsedSeconds, s.TimestampMs, s.HeartRate, s.SpeedMps, s.DistanceM, s.ElevationM); err != nil {
+			return fmt.Errorf("insert sample for activity %d: %w", activityID, err)
+		}
+	}
+	return tx.Commit()
+}
+
+// SamplesForActivity returns all samples for an activity, ordered by elapsed_seconds.
+func (db *DB) SamplesForActivity(ctx context.Context, activityID int64) ([]Sample, error) {
+	rows, err := db.QueryContext(ctx, `
+		SELECT elapsed_seconds, timestamp_ms, heart_rate, speed_mps, distance_m, elevation_m
+		FROM activity_samples WHERE activity_id = ? ORDER BY elapsed_seconds`, activityID)
+	if err != nil {
+		return nil, fmt.Errorf("samples for activity %d: %w", activityID, err)
+	}
+	defer rows.Close()
+
+	samples := []Sample{}
+	for rows.Next() {
+		var s Sample
+		if err := rows.Scan(&s.ElapsedSeconds, &s.TimestampMs, &s.HeartRate, &s.SpeedMps, &s.DistanceM, &s.ElevationM); err != nil {
+			return nil, fmt.Errorf("scan sample row: %w", err)
+		}
+		samples = append(samples, s)
+	}
+	return samples, rows.Err()
+}