fix: Migration 022 - remove invalid schema_migrations tracking

The migration system tracks migrations via filename automatically.
Removed manual DO block that used wrong column name (version vs filename).

Also removed unused json import from goals.py.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/migrations/022_goal_system.sql

@@ -133,15 +133,3 @@ CREATE INDEX IF NOT EXISTS idx_fitness_tests_date ON fitness_tests(profile_id, t
 COMMENT ON TABLE fitness_tests IS 'Standardized fitness tests (Cooper, step test, strength tests, etc.)';
 COMMENT ON COLUMN fitness_tests.test_type IS 'cooper_12min, step_test, pushups_max, plank_max, flexibility_sit_reach, vo2max_est, strength_1rm_squat, strength_1rm_bench';
 COMMENT ON COLUMN fitness_tests.norm_category IS 'Performance category based on age/gender norms';
-
--- ============================================================================
--- VERSION UPDATE
--- ============================================================================
-
--- Track migration
-DO $$
-BEGIN
-  IF NOT EXISTS (SELECT 1 FROM schema_migrations WHERE version = '022') THEN
-    INSERT INTO schema_migrations (version, applied_at) VALUES ('022', NOW());
-  END IF;
-END $$;

backend/routers/goals.py

@@ -14,7 +14,6 @@ from pydantic import BaseModel
 from typing import Optional, List
 from datetime import date, datetime, timedelta
 from decimal import Decimal
-import json
 
 from db import get_db, get_cursor, r2d
 from auth import require_auth