feat: add v9c subscription system database schema

Phase 1: Database Migration Complete

Created migration infrastructure:
- backend/migrations/v9c_subscription_system.sql (11 new tables)
- backend/apply_v9c_migration.py (auto-migration runner)
- Updated main.py startup event to apply migration

New tables (Feature-Registry Pattern):
1. app_settings - Global configuration
2. tiers - Subscription tiers (free/basic/premium/selfhosted)
3. features - Feature registry (11 limitable features)
4. tier_limits - Tier x Feature matrix (44 initial limits)
5. user_feature_restrictions - Individual user overrides
6. user_feature_usage - Usage tracking with reset periods
7. coupons - Coupon management (single-use, period, Wellpass)
8. coupon_redemptions - Redemption history
9. access_grants - Time-limited access with pause/resume logic
10. user_activity_log - Activity tracking (JSONB details)
11. user_stats - Aggregated statistics

Extended profiles table:
- tier, trial_ends_at, email_verified, email_verify_token
- invited_by, invitation_token

Initial data inserted:
- 4 tiers (free/basic/premium/selfhosted)
- 11 features (weight, circumference, caliper, nutrition, activity, photos, ai_calls, ai_pipeline, export_*)
- 44 tier_limits (complete Tier x Feature matrix)
- App settings (trial duration, self-registration config)

Migration auto-runs on container startup (similar to SQLite→PostgreSQL).

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

backend/apply_v9c_migration.py

@@ -0,0 +1,117 @@
+#!/usr/bin/env python3
+"""
+Apply v9c Subscription System Migration
+
+This script checks if v9c migration is needed and applies it.
+Run automatically on container startup via main.py startup event.
+"""
+import os
+import psycopg2
+from psycopg2.extras import RealDictCursor
+
+
+def get_db_connection():
+    """Get PostgreSQL connection."""
+    return psycopg2.connect(
+        host=os.getenv("DB_HOST", "postgres"),
+        port=int(os.getenv("DB_PORT", 5432)),
+        database=os.getenv("DB_NAME", "mitai_prod"),
+        user=os.getenv("DB_USER", "mitai_prod"),
+        password=os.getenv("DB_PASSWORD", ""),
+        cursor_factory=RealDictCursor
+    )
+
+
+def migration_needed(conn):
+    """Check if v9c migration is needed."""
+    cur = conn.cursor()
+
+    # Check if tiers table exists
+    cur.execute("""
+        SELECT EXISTS (
+            SELECT FROM information_schema.tables
+            WHERE table_name = 'tiers'
+        )
+    """)
+    tiers_exists = cur.fetchone()['exists']
+
+    # Check if features table exists
+    cur.execute("""
+        SELECT EXISTS (
+            SELECT FROM information_schema.tables
+            WHERE table_name = 'features'
+        )
+    """)
+    features_exists = cur.fetchone()['exists']
+
+    cur.close()
+
+    # Migration needed if either table is missing
+    return not (tiers_exists and features_exists)
+
+
+def apply_migration():
+    """Apply v9c migration if needed."""
+    print("[v9c Migration] Checking if migration is needed...")
+
+    try:
+        conn = get_db_connection()
+
+        if not migration_needed(conn):
+            print("[v9c Migration] Already applied, skipping.")
+            conn.close()
+            return
+
+        print("[v9c Migration] Applying subscription system migration...")
+
+        # Read migration SQL
+        migration_path = os.path.join(
+            os.path.dirname(__file__),
+            "migrations",
+            "v9c_subscription_system.sql"
+        )
+
+        with open(migration_path, 'r', encoding='utf-8') as f:
+            migration_sql = f.read()
+
+        # Execute migration
+        cur = conn.cursor()
+        cur.execute(migration_sql)
+        conn.commit()
+        cur.close()
+        conn.close()
+
+        print("[v9c Migration] ✅ Migration completed successfully!")
+
+        # Verify tables created
+        conn = get_db_connection()
+        cur = conn.cursor()
+        cur.execute("""
+            SELECT table_name FROM information_schema.tables
+            WHERE table_schema = 'public'
+            AND table_name IN ('tiers', 'features', 'tier_limits', 'access_grants', 'coupons')
+            ORDER BY table_name
+        """)
+        tables = [r['table_name'] for r in cur.fetchall()]
+        print(f"[v9c Migration] Created tables: {', '.join(tables)}")
+
+        # Verify initial data
+        cur.execute("SELECT COUNT(*) as count FROM tiers")
+        tier_count = cur.fetchone()['count']
+        cur.execute("SELECT COUNT(*) as count FROM features")
+        feature_count = cur.fetchone()['count']
+        cur.execute("SELECT COUNT(*) as count FROM tier_limits")
+        limit_count = cur.fetchone()['count']
+
+        print(f"[v9c Migration] Initial data: {tier_count} tiers, {feature_count} features, {limit_count} tier limits")
+
+        cur.close()
+        conn.close()
+
+    except Exception as e:
+        print(f"[v9c Migration] ❌ Error: {e}")
+        raise
+
+
+if __name__ == "__main__":
+    apply_migration()

backend/main.py

@@ -51,6 +51,13 @@ async def startup_event():
         print(f"⚠️  init_db() failed (non-fatal): {e}")
         # Don't crash on startup - can be created manually
 
+    # Apply v9c migration if needed
+    try:
+        from apply_v9c_migration import apply_migration
+        apply_migration()
+    except Exception as e:
+        print(f"⚠️  v9c migration failed (non-fatal): {e}")
+
 # ── Register Routers ──────────────────────────────────────────────────────────
 app.include_router(auth.router)           # /api/auth/*
 app.include_router(profiles.router)       # /api/profiles/*, /api/profile
@@ -71,4 +78,4 @@ app.include_router(importdata.router)     # /api/import/*
 @app.get("/")
 def root():
     """API health check."""
-    return {"status": "ok", "service": "mitai-jinkendo", "version": "v9b"}
+    return {"status": "ok", "service": "mitai-jinkendo", "version": "v9c-dev"}

backend/migrations/v9c_subscription_system.sql

@@ -0,0 +1,352 @@
+-- ============================================================================
+-- Mitai Jinkendo v9c: Subscription & Coupon System Migration
+-- ============================================================================
+-- Created: 2026-03-19
+-- Purpose: Add flexible tier system with Feature-Registry Pattern
+--
+-- Tables added:
+--   1. app_settings          - Global configuration
+--   2. tiers                 - Subscription tiers (simplified)
+--   3. features              - Feature registry (all limitable features)
+--   4. tier_limits           - Tier x Feature matrix
+--   5. user_feature_restrictions - Individual user overrides
+--   6. user_feature_usage    - Usage tracking
+--   7. coupons               - Coupon management
+--   8. coupon_redemptions    - Redemption history
+--   9. access_grants         - Time-limited access grants
+--  10. user_activity_log     - Activity tracking
+--  11. user_stats            - Aggregated statistics
+--
+-- Feature-Registry Pattern:
+--   Instead of hardcoded columns (max_weight_entries, max_ai_calls),
+--   all limits are defined in features table and configured via tier_limits.
+--   This allows adding new limitable features without schema changes.
+-- ============================================================================
+
+-- ============================================================================
+-- 1. app_settings - Global configuration
+-- ============================================================================
+CREATE TABLE IF NOT EXISTS app_settings (
+    key TEXT PRIMARY KEY,
+    value TEXT NOT NULL,
+    description TEXT,
+    updated TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+);
+
+-- ============================================================================
+-- 2. tiers - Subscription tiers (simplified)
+-- ============================================================================
+CREATE TABLE IF NOT EXISTS tiers (
+    id TEXT PRIMARY KEY,              -- 'free', 'basic', 'premium', 'selfhosted'
+    name TEXT NOT NULL,               -- Display name
+    description TEXT,                 -- Marketing description
+    price_monthly_cents INTEGER,      -- NULL for free/selfhosted
+    price_yearly_cents INTEGER,       -- NULL for free/selfhosted
+    stripe_price_id_monthly TEXT,     -- Stripe Price ID (for v9d)
+    stripe_price_id_yearly TEXT,      -- Stripe Price ID (for v9d)
+    active BOOLEAN DEFAULT true,      -- Can new users subscribe?
+    sort_order INTEGER DEFAULT 0,
+    created TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    updated TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+);
+
+-- ============================================================================
+-- 3. features - Feature registry (all limitable features)
+-- ============================================================================
+CREATE TABLE IF NOT EXISTS features (
+    id TEXT PRIMARY KEY,              -- 'weight_entries', 'ai_calls', 'photos', etc.
+    name TEXT NOT NULL,               -- Display name
+    description TEXT,                 -- What is this feature?
+    category TEXT,                    -- 'data', 'ai', 'export', 'integration'
+    limit_type TEXT DEFAULT 'count',  -- 'count', 'boolean', 'quota'
+    reset_period TEXT DEFAULT 'never', -- 'never', 'monthly', 'daily'
+    default_limit INTEGER,            -- Fallback if no tier_limit defined
+    active BOOLEAN DEFAULT true,      -- Is this feature currently used?
+    created TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    updated TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+);
+
+-- ============================================================================
+-- 4. tier_limits - Tier x Feature matrix
+-- ============================================================================
+CREATE TABLE IF NOT EXISTS tier_limits (
+    id TEXT PRIMARY KEY DEFAULT gen_random_uuid()::TEXT,
+    tier_id TEXT NOT NULL REFERENCES tiers(id) ON DELETE CASCADE,
+    feature_id TEXT NOT NULL REFERENCES features(id) ON DELETE CASCADE,
+    limit_value INTEGER,              -- NULL = unlimited, 0 = disabled
+    created TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    updated TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    UNIQUE(tier_id, feature_id)
+);
+
+-- ============================================================================
+-- 5. user_feature_restrictions - Individual user overrides
+-- ============================================================================
+CREATE TABLE IF NOT EXISTS user_feature_restrictions (
+    id TEXT PRIMARY KEY DEFAULT gen_random_uuid()::TEXT,
+    profile_id TEXT NOT NULL REFERENCES profiles(id) ON DELETE CASCADE,
+    feature_id TEXT NOT NULL REFERENCES features(id) ON DELETE CASCADE,
+    limit_value INTEGER,              -- NULL = unlimited, 0 = disabled
+    reason TEXT,                      -- Why was this override applied?
+    created_by TEXT,                  -- Admin profile_id
+    created TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    updated TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    UNIQUE(profile_id, feature_id)
+);
+
+-- ============================================================================
+-- 6. user_feature_usage - Usage tracking
+-- ============================================================================
+CREATE TABLE IF NOT EXISTS user_feature_usage (
+    id TEXT PRIMARY KEY DEFAULT gen_random_uuid()::TEXT,
+    profile_id TEXT NOT NULL REFERENCES profiles(id) ON DELETE CASCADE,
+    feature_id TEXT NOT NULL REFERENCES features(id) ON DELETE CASCADE,
+    usage_count INTEGER DEFAULT 0,
+    reset_at TIMESTAMP,               -- When does this counter reset?
+    created TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    updated TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    UNIQUE(profile_id, feature_id)
+);
+
+-- ============================================================================
+-- 7. coupons - Coupon management
+-- ============================================================================
+CREATE TABLE IF NOT EXISTS coupons (
+    id TEXT PRIMARY KEY DEFAULT gen_random_uuid()::TEXT,
+    code TEXT UNIQUE NOT NULL,
+    type TEXT NOT NULL,               -- 'single_use', 'period', 'wellpass'
+    tier_id TEXT REFERENCES tiers(id) ON DELETE SET NULL,
+    duration_days INTEGER,            -- For period/wellpass coupons
+    max_redemptions INTEGER,          -- NULL = unlimited
+    redemption_count INTEGER DEFAULT 0,
+    valid_from TIMESTAMP,
+    valid_until TIMESTAMP,
+    active BOOLEAN DEFAULT true,
+    created_by TEXT,                  -- Admin profile_id
+    description TEXT,                 -- Internal note
+    created TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    updated TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+);
+
+-- ============================================================================
+-- 8. coupon_redemptions - Redemption history
+-- ============================================================================
+CREATE TABLE IF NOT EXISTS coupon_redemptions (
+    id TEXT PRIMARY KEY DEFAULT gen_random_uuid()::TEXT,
+    coupon_id TEXT NOT NULL REFERENCES coupons(id) ON DELETE CASCADE,
+    profile_id TEXT NOT NULL REFERENCES profiles(id) ON DELETE CASCADE,
+    redeemed_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    access_grant_id TEXT,             -- FK to access_grants (created as result)
+    UNIQUE(coupon_id, profile_id)     -- One redemption per user per coupon
+);
+
+-- ============================================================================
+-- 9. access_grants - Time-limited access grants
+-- ============================================================================
+CREATE TABLE IF NOT EXISTS access_grants (
+    id TEXT PRIMARY KEY DEFAULT gen_random_uuid()::TEXT,
+    profile_id TEXT NOT NULL REFERENCES profiles(id) ON DELETE CASCADE,
+    tier_id TEXT NOT NULL REFERENCES tiers(id) ON DELETE CASCADE,
+    granted_by TEXT,                  -- 'coupon', 'admin', 'trial', 'subscription'
+    coupon_id TEXT REFERENCES coupons(id) ON DELETE SET NULL,
+    valid_from TIMESTAMP NOT NULL,
+    valid_until TIMESTAMP NOT NULL,
+    is_active BOOLEAN DEFAULT true,   -- Can be paused by Wellpass logic
+    paused_by TEXT,                   -- access_grant.id that paused this
+    paused_at TIMESTAMP,              -- When was it paused?
+    remaining_days INTEGER,           -- Days left when paused (for resume)
+    created TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    updated TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+);
+
+-- ============================================================================
+-- 10. user_activity_log - Activity tracking
+-- ============================================================================
+CREATE TABLE IF NOT EXISTS user_activity_log (
+    id TEXT PRIMARY KEY DEFAULT gen_random_uuid()::TEXT,
+    profile_id TEXT NOT NULL REFERENCES profiles(id) ON DELETE CASCADE,
+    action TEXT NOT NULL,             -- 'login', 'logout', 'coupon_redeemed', 'tier_changed'
+    details JSONB,                    -- Flexible metadata
+    ip_address TEXT,
+    user_agent TEXT,
+    created TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+);
+
+CREATE INDEX IF NOT EXISTS idx_activity_log_profile ON user_activity_log(profile_id, created DESC);
+CREATE INDEX IF NOT EXISTS idx_activity_log_action ON user_activity_log(action, created DESC);
+
+-- ============================================================================
+-- 11. user_stats - Aggregated statistics
+-- ============================================================================
+CREATE TABLE IF NOT EXISTS user_stats (
+    profile_id TEXT PRIMARY KEY REFERENCES profiles(id) ON DELETE CASCADE,
+    last_login TIMESTAMP,
+    login_count INTEGER DEFAULT 0,
+    weight_entries_count INTEGER DEFAULT 0,
+    ai_calls_count INTEGER DEFAULT 0,
+    photos_count INTEGER DEFAULT 0,
+    total_data_points INTEGER DEFAULT 0,
+    created TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    updated TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+);
+
+-- ============================================================================
+-- Extend profiles table with subscription fields
+-- ============================================================================
+ALTER TABLE profiles ADD COLUMN IF NOT EXISTS tier TEXT DEFAULT 'free';
+ALTER TABLE profiles ADD COLUMN IF NOT EXISTS trial_ends_at TIMESTAMP;
+ALTER TABLE profiles ADD COLUMN IF NOT EXISTS email_verified BOOLEAN DEFAULT false;
+ALTER TABLE profiles ADD COLUMN IF NOT EXISTS email_verify_token TEXT;
+ALTER TABLE profiles ADD COLUMN IF NOT EXISTS invited_by TEXT REFERENCES profiles(id) ON DELETE SET NULL;
+ALTER TABLE profiles ADD COLUMN IF NOT EXISTS invitation_token TEXT;
+
+-- ============================================================================
+-- Insert initial data
+-- ============================================================================
+
+-- App settings
+INSERT INTO app_settings (key, value, description) VALUES
+    ('trial_duration_days', '14', 'Default trial duration for new registrations'),
+    ('post_trial_tier', 'free', 'Tier after trial expires (free/disabled)'),
+    ('require_email_verification', 'true', 'Require email verification before activation'),
+    ('self_registration_enabled', 'true', 'Allow self-registration')
+ON CONFLICT (key) DO NOTHING;
+
+-- Tiers
+INSERT INTO tiers (id, name, description, price_monthly_cents, price_yearly_cents, active, sort_order) VALUES
+    ('free', 'Free', 'Eingeschränkte Basis-Funktionen', NULL, NULL, true, 1),
+    ('basic', 'Basic', 'Kernfunktionen ohne KI', 499, 4990, true, 2),
+    ('premium', 'Premium', 'Alle Features inkl. KI und Connectoren', 999, 9990, true, 3),
+    ('selfhosted', 'Self-Hosted', 'Unbegrenzt (für Heimserver)', NULL, NULL, false, 4)
+ON CONFLICT (id) DO NOTHING;
+
+-- Features (11 initial features)
+INSERT INTO features (id, name, description, category, limit_type, reset_period, default_limit, active) VALUES
+    ('weight_entries', 'Gewichtseinträge', 'Anzahl Gewichtsmessungen', 'data', 'count', 'never', NULL, true),
+    ('circumference_entries', 'Umfangs-Einträge', 'Anzahl Umfangsmessungen', 'data', 'count', 'never', NULL, true),
+    ('caliper_entries', 'Caliper-Einträge', 'Anzahl Hautfaltenmessungen', 'data', 'count', 'never', NULL, true),
+    ('nutrition_entries', 'Ernährungs-Einträge', 'Anzahl Ernährungslogs', 'data', 'count', 'never', NULL, true),
+    ('activity_entries', 'Aktivitäts-Einträge', 'Anzahl Trainings/Aktivitäten', 'data', 'count', 'never', NULL, true),
+    ('photos', 'Progress-Fotos', 'Anzahl hochgeladene Fotos', 'data', 'count', 'never', NULL, true),
+    ('ai_calls', 'KI-Analysen', 'KI-Auswertungen pro Monat', 'ai', 'count', 'monthly', 0, true),
+    ('ai_pipeline', 'KI-Pipeline', 'Vollständige Pipeline-Analyse', 'ai', 'boolean', 'never', 0, true),
+    ('export_csv', 'CSV-Export', 'Daten als CSV exportieren', 'export', 'boolean', 'never', 0, true),
+    ('export_json', 'JSON-Export', 'Daten als JSON exportieren', 'export', 'boolean', 'never', 0, true),
+    ('export_zip', 'ZIP-Export', 'Vollständiger Backup-Export', 'export', 'boolean', 'never', 0, true)
+ON CONFLICT (id) DO NOTHING;
+
+-- Tier x Feature Matrix (tier_limits)
+-- Format: (tier, feature, limit) - NULL = unlimited, 0 = disabled
+
+-- FREE tier (sehr eingeschränkt)
+INSERT INTO tier_limits (tier_id, feature_id, limit_value) VALUES
+    ('free', 'weight_entries', 30),
+    ('free', 'circumference_entries', 10),
+    ('free', 'caliper_entries', 10),
+    ('free', 'nutrition_entries', 30),
+    ('free', 'activity_entries', 30),
+    ('free', 'photos', 5),
+    ('free', 'ai_calls', 0),           -- Keine KI
+    ('free', 'ai_pipeline', 0),        -- Keine Pipeline
+    ('free', 'export_csv', 0),         -- Kein Export
+    ('free', 'export_json', 0),
+    ('free', 'export_zip', 0)
+ON CONFLICT (tier_id, feature_id) DO NOTHING;
+
+-- BASIC tier (Kernfunktionen)
+INSERT INTO tier_limits (tier_id, feature_id, limit_value) VALUES
+    ('basic', 'weight_entries', NULL),     -- Unbegrenzt
+    ('basic', 'circumference_entries', NULL),
+    ('basic', 'caliper_entries', NULL),
+    ('basic', 'nutrition_entries', NULL),
+    ('basic', 'activity_entries', NULL),
+    ('basic', 'photos', 50),
+    ('basic', 'ai_calls', 3),              -- 3 KI-Calls/Monat
+    ('basic', 'ai_pipeline', 0),           -- Keine Pipeline
+    ('basic', 'export_csv', 1),            -- Export erlaubt
+    ('basic', 'export_json', 1),
+    ('basic', 'export_zip', 1)
+ON CONFLICT (tier_id, feature_id) DO NOTHING;
+
+-- PREMIUM tier (alles unbegrenzt)
+INSERT INTO tier_limits (tier_id, feature_id, limit_value) VALUES
+    ('premium', 'weight_entries', NULL),
+    ('premium', 'circumference_entries', NULL),
+    ('premium', 'caliper_entries', NULL),
+    ('premium', 'nutrition_entries', NULL),
+    ('premium', 'activity_entries', NULL),
+    ('premium', 'photos', NULL),
+    ('premium', 'ai_calls', NULL),         -- Unbegrenzt KI
+    ('premium', 'ai_pipeline', 1),         -- Pipeline erlaubt
+    ('premium', 'export_csv', 1),
+    ('premium', 'export_json', 1),
+    ('premium', 'export_zip', 1)
+ON CONFLICT (tier_id, feature_id) DO NOTHING;
+
+-- SELFHOSTED tier (alles unbegrenzt)
+INSERT INTO tier_limits (tier_id, feature_id, limit_value) VALUES
+    ('selfhosted', 'weight_entries', NULL),
+    ('selfhosted', 'circumference_entries', NULL),
+    ('selfhosted', 'caliper_entries', NULL),
+    ('selfhosted', 'nutrition_entries', NULL),
+    ('selfhosted', 'activity_entries', NULL),
+    ('selfhosted', 'photos', NULL),
+    ('selfhosted', 'ai_calls', NULL),
+    ('selfhosted', 'ai_pipeline', 1),
+    ('selfhosted', 'export_csv', 1),
+    ('selfhosted', 'export_json', 1),
+    ('selfhosted', 'export_zip', 1)
+ON CONFLICT (tier_id, feature_id) DO NOTHING;
+
+-- ============================================================================
+-- Migrate existing profiles
+-- ============================================================================
+
+-- Lars' Profile → selfhosted tier with email verified
+UPDATE profiles
+SET
+    tier = 'selfhosted',
+    email_verified = true
+WHERE
+    email = 'lars@stommer.com'
+    OR role = 'admin';
+
+-- Other existing profiles → free tier, unverified
+UPDATE profiles
+SET
+    tier = 'free',
+    email_verified = false
+WHERE
+    tier IS NULL
+    OR tier = '';
+
+-- Initialize user_stats for existing profiles
+INSERT INTO user_stats (profile_id, weight_entries_count, photos_count)
+SELECT
+    p.id,
+    (SELECT COUNT(*) FROM weight_log WHERE profile_id = p.id),
+    (SELECT COUNT(*) FROM photos WHERE profile_id = p.id)
+FROM profiles p
+ON CONFLICT (profile_id) DO NOTHING;
+
+-- ============================================================================
+-- Create indexes for performance
+-- ============================================================================
+CREATE INDEX IF NOT EXISTS idx_tier_limits_tier ON tier_limits(tier_id);
+CREATE INDEX IF NOT EXISTS idx_tier_limits_feature ON tier_limits(feature_id);
+CREATE INDEX IF NOT EXISTS idx_user_restrictions_profile ON user_feature_restrictions(profile_id);
+CREATE INDEX IF NOT EXISTS idx_user_usage_profile ON user_feature_usage(profile_id);
+CREATE INDEX IF NOT EXISTS idx_access_grants_profile ON access_grants(profile_id, valid_until DESC);
+CREATE INDEX IF NOT EXISTS idx_access_grants_active ON access_grants(profile_id, is_active, valid_until DESC);
+CREATE INDEX IF NOT EXISTS idx_coupons_code ON coupons(code);
+CREATE INDEX IF NOT EXISTS idx_coupon_redemptions_profile ON coupon_redemptions(profile_id);
+
+-- ============================================================================
+-- Migration complete
+-- ============================================================================
+-- Run this migration with:
+-- psql -h localhost -U mitai_prod -d mitai_prod < backend/migrations/v9c_subscription_system.sql
+--
+-- Or via Docker:
+-- docker exec -i mitai-postgres psql -U mitai_prod -d mitai_prod < backend/migrations/v9c_subscription_system.sql
+-- ============================================================================