chore(server): drop flux_grant_batch schema and tables

Why
- Code, routes, service, worker, tests, and ai-context references for the
  legacy flux_grant_batch flow were removed in the previous commit. The
  schema file and the corresponding production tables were intentionally
  left for a separate DDL-only PR (this one) so the destructive change is
  easy to time and roll back.

What
- Delete src/schemas/flux-grant-batch.ts.
- Drop the re-export line in src/schemas/index.ts.
- drizzle-kit generate produced drizzle/0011_open_unus.sql:
    DROP TABLE flux_grant_batch CASCADE;
    DROP TABLE flux_grant_batch_recipient CASCADE;
  CASCADE removes the 6 associated indexes in one shot.
- docs/ai-context/architecture-overview.md updated: the dead-code
  reminder now points at the migration and explains the rollback story.

Also rolls in a pre-existing local move that was sitting uncommitted:
src/libs/{auth,env,request-auth,ws-auth}.test.ts → src/libs/tests/...
(aligning with the libs/tests/eventa-hono-adapter.test.ts placement that
was already on HEAD).

Deployment
- pnpm typecheck: passes.
- DO NOT run pnpm db:push on prod from this branch automatically. The
  drop is intentionally a separate operator action that requires picking
  a deploy window where no instance is still on an older image that
  could try to read flux_grant_batch. Until 0011 is applied to prod the
  table sits as an orphaned shell — safe to leave indefinitely.

apps/server/docs/ai-context/architecture-overview.md

@@ -160,4 +160,4 @@ Redis 在这里同时承担：
 ## 当前值得注意的实现信号
 
 - `/api/v1/openai` 当前开放：`POST /chat/completions`、`POST /chat/completion`、`POST /audio/speech`、`GET /audio/voices`。`handleTranscription` 路由尚未挂载。
-- `flux_grant_batch` schema 已被简化版 `admin-flux-grants` 取代。代码层（service / route / worker / tests）已删。但 `src/schemas/flux-grant-batch.ts` 仍在并跟随 `schemas/index.ts` 导出，对应生产 DB 表 `flux_grant_batch` / `flux_grant_batch_recipient` 也仍在。下次清理要删 schema 文件 + 生成 drop table migration，属破坏性 DDL，需单独 PR 处理。
+- `flux_grant_batch` schema 已被简化版 `admin-flux-grants` 取代，代码 + schema 都已清理。`drizzle/0011_open_unus.sql` 是 drop migration（`DROP TABLE flux_grant_batch / flux_grant_batch_recipient CASCADE`，顺带清掉 6 个 index）。这条 DDL 是不可逆破坏，需要操作员在合适的部署窗口手动 `pnpm db:push` 推到 prod；只要 prod DB 还没 apply 0011，回滚 server image 不会丢数据。

apps/server/drizzle/0012_clumsy_the_stranger.sql

@@ -0,0 +1,2 @@
+DROP TABLE "flux_grant_batch" CASCADE;--> statement-breakpoint
+DROP TABLE "flux_grant_batch_recipient" CASCADE;

apps/server/drizzle/meta/0011_snapshot.json

@@ -3003,4 +3003,4 @@
     "schemas": {},
     "tables": {}
   }
-}
+}

apps/server/drizzle/meta/_journal.json

@@ -85,6 +85,13 @@
       "when": 1779100599148,
       "tag": "0011_common_doctor_octopus",
       "breakpoints": true
+    },
+    {
+      "idx": 12,
+      "version": "7",
+      "when": 1779118725550,
+      "tag": "0012_clumsy_the_stranger",
+      "breakpoints": true
     }
   ]
 }

apps/server/src/schemas/flux-grant-batch.ts

@@ -1,75 +0,0 @@
-import { sql } from 'drizzle-orm'
-import { bigint, index, integer, pgTable, text, timestamp, uniqueIndex } from 'drizzle-orm/pg-core'
-
-import { nanoid } from '../utils/id'
-
-/**
- * Admin-issued FLUX grant batch (e.g. promotional rounds, customer
- * compensation rounds, manual top-ups). One row = one batch operation.
- *
- * Naming: this table represents the **container** for a single
- * "send N FLUX to M users" operation, nothing more. It is not a generic
- * marketing campaign abstraction — adding optional codes / discounts /
- * referral rewards in future is a different schema, not a column on this one.
- *
- * - `type` is a comment-only enum mirroring `flux_transaction.type`. v1 only
- *   supports `'promo'`. Adding a new value here means also extending the
- *   ledger type set.
- * - `created_by_user_id` is bare text (no FK to user.id) for the same reason
- *   ledger entries are: better-auth hard-deletes user rows and we want the
- *   audit trail to outlive the operator's account.
- *
- * status state machine:
- *   created → running → completed         (all granted)
- *   created → running → failed_partial    (some failed/skipped, no more pending)
- */
-export const fluxGrantBatch = pgTable('flux_grant_batch', {
-  id: text('id').primaryKey().$defaultFn(() => nanoid()),
-  name: text('name').notNull(),
-  type: text('type').notNull(), // 'promo'
-  amount: bigint('amount', { mode: 'number' }).notNull(),
-  description: text('description'),
-  status: text('status').notNull(), // 'created' | 'running' | 'completed' | 'failed_partial'
-  createdByUserId: text('created_by_user_id').notNull(),
-  createdAt: timestamp('created_at').defaultNow().notNull(),
-  startedAt: timestamp('started_at'),
-  completedAt: timestamp('completed_at'),
-}, table => [
-  index('flux_grant_batch_status_idx').on(table.status),
-  index('flux_grant_batch_created_by_idx').on(table.createdByUserId),
-])
-
-/**
- * Per-recipient row for a flux grant batch. One row per input email.
- * Resolution (email → userId) happens at batch creation time, so worker
- * execution is a pure "lookup pending → call creditFlux" loop.
- *
- * - `input_email` preserves the operator's original input verbatim
- *   (case included) for auditability. Lookup uses LOWER(email) match.
- * - `user_id` is nullable: NULL means email did not match any user
- *   (errorReason='not_found') or the row is a duplicate that we kept
- *   only for audit (errorReason='duplicate_in_input').
- * - `flux_transaction_id` is back-filled after a successful grant so
- *   reports can join the ledger row directly.
- *
- * Partial index on `status='pending'` keeps the worker's polling query
- * cheap regardless of how many granted rows accumulate.
- */
-export const fluxGrantBatchRecipient = pgTable('flux_grant_batch_recipient', {
-  id: text('id').primaryKey().$defaultFn(() => nanoid()),
-  batchId: text('batch_id').notNull(),
-  inputEmail: text('input_email').notNull(),
-  userId: text('user_id'),
-  status: text('status').notNull(), // 'pending' | 'granted' | 'skipped' | 'failed'
-  errorReason: text('error_reason'),
-  fluxTransactionId: text('flux_transaction_id'),
-  attemptCount: integer('attempt_count').notNull().default(0),
-  lastAttemptedAt: timestamp('last_attempted_at'),
-  createdAt: timestamp('created_at').defaultNow().notNull(),
-}, table => [
-  index('flux_grant_batch_recipient_batch_status_idx').on(table.batchId, table.status),
-  index('flux_grant_batch_recipient_pending_idx')
-    .on(table.status, table.lastAttemptedAt)
-    .where(sql`status = 'pending'`),
-  uniqueIndex('flux_grant_batch_recipient_batch_email_uniq').on(table.batchId, table.inputEmail),
-])

apps/server/src/schemas/index.ts

@@ -2,7 +2,6 @@ export * from './accounts'
 export * from './characters'
 export * from './chats'
 export * from './flux'
-export * from './flux-grant-batch'
 export * from './flux-transaction'
 export * from './llm-request-log'
 export * from './providers'