merge: maestro/tsk_tFMU7-hKzfOf [tsk_tFMU7-hKzfOf] codes 激活码模块

解决与 1A 骨架的冲突：module 统一为 github.com/wangjia/pangolin/server
（codes 分支原用 pangolin/server，7 个源文件 import 已改写）；
go.mod require 并集(redis 取 9.20.1)；Makefile 以骨架为基底并入
build-codegen/test-unit/test-integration target。
go build/vet 通过，codes 单测通过。

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

server/migrations/001_init.sql

@@ -0,0 +1,94 @@
+-- Migration 001: baseline schema for the codes module and its dependencies.
+-- MySQL 8.x · InnoDB · utf8mb4 · UTC
+-- Apply with: mysql -u root -p pangolin < migrations/001_init.sql
+
+SET time_zone = '+00:00';
+
+-- -------------------------------------------------------------------------
+-- Core account tables (needed by foreign keys from subscriptions)
+-- -------------------------------------------------------------------------
+
+CREATE TABLE IF NOT EXISTS users (
+  id          BIGINT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
+  uuid        CHAR(36)     NOT NULL UNIQUE,          -- public-facing identifier
+  email       VARCHAR(255) NOT NULL UNIQUE,
+  pw_hash     VARCHAR(255) NOT NULL,                 -- argon2id
+  dp_uuid     CHAR(36)     NOT NULL,                 -- data-plane UUID (sing-box)
+  status      ENUM('active','banned') NOT NULL DEFAULT 'active',
+  created_at  DATETIME(6)  NOT NULL DEFAULT CURRENT_TIMESTAMP(6)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
+
+-- -------------------------------------------------------------------------
+-- Plan catalogue  (digital values per design/CLAUDE.md §7)
+-- -------------------------------------------------------------------------
+
+CREATE TABLE IF NOT EXISTS plans (
+  id            BIGINT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
+  code          ENUM('free','pro','team') NOT NULL UNIQUE,
+  max_devices   INT  NOT NULL,              -- free 1 / pro 5 / team 10
+  daily_minutes INT  NULL,                  -- free 10; NULL = unlimited
+  ad_gate       BOOLEAN NOT NULL DEFAULT FALSE  -- free users must watch an ad daily
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
+
+INSERT IGNORE INTO plans (code, max_devices, daily_minutes, ad_gate) VALUES
+  ('free', 1,  10,   TRUE),
+  ('pro',  5,  NULL, FALSE),
+  ('team', 10, NULL, FALSE);
+
+-- -------------------------------------------------------------------------
+-- Subscriptions
+-- -------------------------------------------------------------------------
+
+CREATE TABLE IF NOT EXISTS subscriptions (
+  id         BIGINT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
+  user_id    BIGINT UNSIGNED NOT NULL,
+  plan_id    BIGINT UNSIGNED NOT NULL,
+  expires_at DATETIME(6) NOT NULL,
+  source     ENUM('trial','code') NOT NULL,
+  created_at DATETIME(6) NOT NULL DEFAULT CURRENT_TIMESTAMP(6),
+  FOREIGN KEY (user_id) REFERENCES users(id),
+  FOREIGN KEY (plan_id) REFERENCES plans(id),
+  INDEX idx_user_exp (user_id, expires_at)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
+
+-- -------------------------------------------------------------------------
+-- Activation-code tables
+-- -------------------------------------------------------------------------
+
+CREATE TABLE IF NOT EXISTS code_batches (
+  id         BIGINT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
+  channel    ENUM('store','tg','line','manual') NOT NULL,
+  created_by VARCHAR(64)  NOT NULL,
+  note       VARCHAR(255) NULL,
+  created_at DATETIME(6)  NOT NULL DEFAULT CURRENT_TIMESTAMP(6)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
+
+CREATE TABLE IF NOT EXISTS codes (
+  id            BIGINT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
+  -- SHA-256(canonical_plaintext) stored as 64-char hex.
+  -- Plaintext NEVER stored in any column.
+  code_hash     CHAR(64)     NOT NULL UNIQUE,
+  plan_id       BIGINT UNSIGNED NOT NULL,
+  duration_days INT          NOT NULL,
+  batch_id      BIGINT UNSIGNED NOT NULL,
+  status        ENUM('unused','redeemed','void') NOT NULL DEFAULT 'unused',
+  redeemed_by   BIGINT UNSIGNED NULL,    -- FK to users.id (not enforced to avoid
+  redeemed_at   DATETIME(6)  NULL,       -- locking the users table on redeem)
+  FOREIGN KEY (plan_id)  REFERENCES plans(id),
+  FOREIGN KEY (batch_id) REFERENCES code_batches(id),
+  INDEX idx_status (status)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
+
+-- -------------------------------------------------------------------------
+-- Audit log  (all sensitive operations must be recorded)
+-- -------------------------------------------------------------------------
+
+CREATE TABLE IF NOT EXISTS audit_log (
+  id     BIGINT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
+  actor  VARCHAR(64)  NOT NULL,           -- e.g. "user:123" or "admin:7"
+  action VARCHAR(64)  NOT NULL,           -- e.g. "redeem", "ban", "node_drain"
+  target VARCHAR(128) NOT NULL,           -- abbreviated; never contains plaintext codes
+  meta   JSON NULL,                       -- structured context (no PII beyond IDs)
+  at     DATETIME(6)  NOT NULL DEFAULT CURRENT_TIMESTAMP(6),
+  INDEX idx_at (at)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;