refactor(migration): merge per-plugin SQL into single initial migration

Each plugin now has exactly one migration file (00001_initial.sql)
containing its complete table schema and seed data, replacing the
multi-file approach with split ALTER/INSERT steps.

Changes per plugin:
- auth: w_auth_sources, w_external_accounts, w_access_tokens + login session seed
- user: w_users + system user seed (removed w_access_tokens — belongs to auth)
- admin: w_system_configs, w_templates + all 32 config seeds + 2 template seeds
  (removed w_schedules, w_task_executions — belong to driver plugins)
- upload: w_upload_stats + indexes + access_mode + backfill
- message_gateway: all w_message_*, w_push_*, w_push_channels, w_push_histories
- risk_control/logstore: w_user_access_logs (PG + ClickHouse)
- driver_asynq_cron: w_schedules + cleanup seed
- driver_asynq_worker: w_task_executions

All CREATE TABLE use IF NOT EXISTS, all INSERT use ON CONFLICT DO NOTHING.
go:embed patterns remain 'migrations/*.sql' — unchanged.

plugins/domain/auth/migrations/00001_initial.sql

@@ -0,0 +1,58 @@
+-- +goose Up
+-- +goose StatementBegin
+CREATE TABLE IF NOT EXISTS w_auth_sources (
+    id BIGINT PRIMARY KEY,
+    name VARCHAR(80) NOT NULL UNIQUE,
+    type VARCHAR(20) NOT NULL,
+    display_name VARCHAR(100),
+    is_active BOOLEAN NOT NULL DEFAULT FALSE,
+    client_id VARCHAR(255),
+    client_secret VARCHAR(1024),
+    openid_discovery_url VARCHAR(1024),
+    scopes VARCHAR(255),
+    icon_url VARCHAR(1024),
+    created_at TIMESTAMPTZ DEFAULT CURRENT_TIMESTAMP,
+    updated_at TIMESTAMPTZ DEFAULT CURRENT_TIMESTAMP
+);
+CREATE INDEX IF NOT EXISTS idx_w_auth_sources_is_active ON w_auth_sources (is_active);
+
+CREATE TABLE IF NOT EXISTS w_external_accounts (
+    id BIGINT PRIMARY KEY,
+    auth_source_id BIGINT,
+    user_id BIGINT NOT NULL,
+    external_id VARCHAR(255) NOT NULL,
+    external_username VARCHAR(255),
+    email VARCHAR(255),
+    created_at TIMESTAMPTZ DEFAULT CURRENT_TIMESTAMP,
+    updated_at TIMESTAMPTZ DEFAULT CURRENT_TIMESTAMP
+);
+CREATE INDEX IF NOT EXISTS idx_w_external_accounts_auth_source_id ON w_external_accounts (auth_source_id);
+CREATE INDEX IF NOT EXISTS idx_w_external_accounts_user_id ON w_external_accounts (user_id);
+CREATE UNIQUE INDEX IF NOT EXISTS idx_w_external_accounts_source_external ON w_external_accounts (auth_source_id, external_id);
+
+CREATE TABLE IF NOT EXISTS w_access_tokens (
+    id BIGINT PRIMARY KEY,
+    user_id BIGINT NOT NULL,
+    token_hash VARCHAR(64) NOT NULL UNIQUE,
+    name VARCHAR(128) NOT NULL,
+    description VARCHAR(255),
+    is_admin BOOLEAN DEFAULT FALSE,
+    expires_at TIMESTAMPTZ,
+    created_at TIMESTAMPTZ DEFAULT CURRENT_TIMESTAMP,
+    updated_at TIMESTAMPTZ DEFAULT CURRENT_TIMESTAMP
+);
+CREATE INDEX IF NOT EXISTS idx_w_access_tokens_user_id ON w_access_tokens (user_id);
+
+-- Seed: login session TTL
+INSERT INTO w_system_configs (key, value, type, visibility, description, created_at, updated_at)
+VALUES ('login_session_ttl_hours', '0', 'system', 0, '登录会话过期时间 (小时，0表示浏览器关闭后自动退出，-1表示永不过期)', CURRENT_TIMESTAMP, CURRENT_TIMESTAMP)
+ON CONFLICT (key) DO NOTHING;
+-- +goose StatementEnd
+
+-- +goose Down
+-- +goose StatementBegin
+DELETE FROM w_system_configs WHERE key = 'login_session_ttl_hours';
+DROP TABLE IF EXISTS w_access_tokens;
+DROP TABLE IF EXISTS w_external_accounts;
+DROP TABLE IF EXISTS w_auth_sources;
+-- +goose StatementEnd