fix: 恢复所有迁移文件以修复校验和错误

恢复了以下迁移文件到原始状态：
- 004_add_redeem_code_notes.sql
- 005_schema_parity.sql
- 006_fix_invalid_subscription_expires_at.sql
- 007_add_user_allowed_groups.sql
- 008_seed_default_group.sql
- 009_fix_usage_logs_cache_columns.sql
- 010_add_usage_logs_aggregated_indexes.sql
- 011_remove_duplicate_unique_indexes.sql
- 012_add_user_subscription_soft_delete.sql
- 013_log_orphan_allowed_groups.sql
- 014_drop_legacy_allowed_groups.sql
- 015_fix_settings_unique_constraint.sql
- 016_soft_delete_partial_unique_indexes.sql
- 018_user_attributes.sql
- 019_migrate_wechat_to_attributes.sql
- 024_add_gemini_tier_id.sql

数据库迁移文件不应在应用后修改，即使只是注释。

backend/migrations/005_schema_parity.sql

@@ -1,42 +1,42 @@
--- Align SQL migrations with current GORM persistence models.
--- This file is designed to be safe on both fresh installs and existing databases.
-
--- users: add fields added after initial migration
-ALTER TABLE users ADD COLUMN IF NOT EXISTS username VARCHAR(100) NOT NULL DEFAULT '';
-ALTER TABLE users ADD COLUMN IF NOT EXISTS wechat VARCHAR(100) NOT NULL DEFAULT '';
-ALTER TABLE users ADD COLUMN IF NOT EXISTS notes TEXT NOT NULL DEFAULT '';
-
--- api_keys: allow longer keys (GORM model uses size:128)
-ALTER TABLE api_keys ALTER COLUMN key TYPE VARCHAR(128);
-
--- accounts: scheduling and rate-limit fields used by repository queries
-ALTER TABLE accounts ADD COLUMN IF NOT EXISTS schedulable BOOLEAN NOT NULL DEFAULT TRUE;
-ALTER TABLE accounts ADD COLUMN IF NOT EXISTS rate_limited_at TIMESTAMPTZ;
-ALTER TABLE accounts ADD COLUMN IF NOT EXISTS rate_limit_reset_at TIMESTAMPTZ;
-ALTER TABLE accounts ADD COLUMN IF NOT EXISTS overload_until TIMESTAMPTZ;
-ALTER TABLE accounts ADD COLUMN IF NOT EXISTS session_window_start TIMESTAMPTZ;
-ALTER TABLE accounts ADD COLUMN IF NOT EXISTS session_window_end TIMESTAMPTZ;
-ALTER TABLE accounts ADD COLUMN IF NOT EXISTS session_window_status VARCHAR(20);
-
-CREATE INDEX IF NOT EXISTS idx_accounts_schedulable ON accounts(schedulable);
-CREATE INDEX IF NOT EXISTS idx_accounts_rate_limited_at ON accounts(rate_limited_at);
-CREATE INDEX IF NOT EXISTS idx_accounts_rate_limit_reset_at ON accounts(rate_limit_reset_at);
-CREATE INDEX IF NOT EXISTS idx_accounts_overload_until ON accounts(overload_until);
-
--- redeem_codes: subscription redeem fields
-ALTER TABLE redeem_codes ADD COLUMN IF NOT EXISTS group_id BIGINT REFERENCES groups(id) ON DELETE SET NULL;
-ALTER TABLE redeem_codes ADD COLUMN IF NOT EXISTS validity_days INT NOT NULL DEFAULT 30;
-CREATE INDEX IF NOT EXISTS idx_redeem_codes_group_id ON redeem_codes(group_id);
-
--- usage_logs: billing type used by filters and stats
-ALTER TABLE usage_logs ADD COLUMN IF NOT EXISTS billing_type SMALLINT NOT NULL DEFAULT 0;
-CREATE INDEX IF NOT EXISTS idx_usage_logs_billing_type ON usage_logs(billing_type);
-
--- settings: key-value store
-CREATE TABLE IF NOT EXISTS settings (
-    id          BIGSERIAL PRIMARY KEY,
-    key         VARCHAR(100) NOT NULL UNIQUE,
-    value       TEXT NOT NULL,
-    updated_at  TIMESTAMPTZ NOT NULL DEFAULT NOW()
-);
-
+-- Align SQL migrations with current GORM persistence models.
+-- This file is designed to be safe on both fresh installs and existing databases.
+
+-- users: add fields added after initial migration
+ALTER TABLE users ADD COLUMN IF NOT EXISTS username VARCHAR(100) NOT NULL DEFAULT '';
+ALTER TABLE users ADD COLUMN IF NOT EXISTS wechat VARCHAR(100) NOT NULL DEFAULT '';
+ALTER TABLE users ADD COLUMN IF NOT EXISTS notes TEXT NOT NULL DEFAULT '';
+
+-- api_keys: allow longer keys (GORM model uses size:128)
+ALTER TABLE api_keys ALTER COLUMN key TYPE VARCHAR(128);
+
+-- accounts: scheduling and rate-limit fields used by repository queries
+ALTER TABLE accounts ADD COLUMN IF NOT EXISTS schedulable BOOLEAN NOT NULL DEFAULT TRUE;
+ALTER TABLE accounts ADD COLUMN IF NOT EXISTS rate_limited_at TIMESTAMPTZ;
+ALTER TABLE accounts ADD COLUMN IF NOT EXISTS rate_limit_reset_at TIMESTAMPTZ;
+ALTER TABLE accounts ADD COLUMN IF NOT EXISTS overload_until TIMESTAMPTZ;
+ALTER TABLE accounts ADD COLUMN IF NOT EXISTS session_window_start TIMESTAMPTZ;
+ALTER TABLE accounts ADD COLUMN IF NOT EXISTS session_window_end TIMESTAMPTZ;
+ALTER TABLE accounts ADD COLUMN IF NOT EXISTS session_window_status VARCHAR(20);
+
+CREATE INDEX IF NOT EXISTS idx_accounts_schedulable ON accounts(schedulable);
+CREATE INDEX IF NOT EXISTS idx_accounts_rate_limited_at ON accounts(rate_limited_at);
+CREATE INDEX IF NOT EXISTS idx_accounts_rate_limit_reset_at ON accounts(rate_limit_reset_at);
+CREATE INDEX IF NOT EXISTS idx_accounts_overload_until ON accounts(overload_until);
+
+-- redeem_codes: subscription redeem fields
+ALTER TABLE redeem_codes ADD COLUMN IF NOT EXISTS group_id BIGINT REFERENCES groups(id) ON DELETE SET NULL;
+ALTER TABLE redeem_codes ADD COLUMN IF NOT EXISTS validity_days INT NOT NULL DEFAULT 30;
+CREATE INDEX IF NOT EXISTS idx_redeem_codes_group_id ON redeem_codes(group_id);
+
+-- usage_logs: billing type used by filters and stats
+ALTER TABLE usage_logs ADD COLUMN IF NOT EXISTS billing_type SMALLINT NOT NULL DEFAULT 0;
+CREATE INDEX IF NOT EXISTS idx_usage_logs_billing_type ON usage_logs(billing_type);
+
+-- settings: key-value store
+CREATE TABLE IF NOT EXISTS settings (
+    id          BIGSERIAL PRIMARY KEY,
+    key         VARCHAR(100) NOT NULL UNIQUE,
+    value       TEXT NOT NULL,
+    updated_at  TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+