chore(格式): Prettier 统一到全仓，后端和契约一次性格式化

原来只有 `apps/web` 在 Prettier 下（配置在 `apps/web/.prettierrc.toml`、脚本在
web 的 package.json），后端和契约从来没格式化过 —— 手写在 100 列上下，`db/schema.ts`
还是 drizzle-kit pull 留下的 tab 缩进。两套口径分叉久了，跨端改一处就得记着「这边
什么风格」。

- 配置搬到根目录 `.prettierrc.toml`，内容不变（`semi=false`，其余全默认，
  printWidth 80 —— 和前端已有的格式一致，不另立一套宽度）；
- 脚本统一成根目录 `bun run fmt`，覆盖 `apps/*/src`、`apps/web/tests` 和两个构建
  配置；web 自己那份 `fmt` 和重复的 prettier 依赖删掉；
- `.prettierignore` 挡掉两类不该碰的：drizzle-kit 生成的 `src/db/meta/` 结构快照
  （它是 db:generate 的比对输入，只该由 drizzle-kit 写）、unplugin 每次 dev 都会
  重写的 `auto-imports.d.ts` / `components.d.ts`；
- 全量跑了一遍。纯格式，无行为改动：api typecheck / check:routes / check:ast、
  前端 type-check 全过，起 api 打了接口确认正常。前端这 39 个文件的小改动是
  prettier 版本漂移（类型断言的换行口径变了），不是新配置带来的。

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

packages/contract/src/flowchart.ts

@@ -2,14 +2,24 @@ import { z } from "zod"
 
 import { paginatedSchema } from "./common"
 
-export const flowchartStatusSchema = z.union([z.literal(0), z.literal(1), z.literal(2), z.literal(3)])
+export const flowchartStatusSchema = z.union([
+  z.literal(0),
+  z.literal(1),
+  z.literal(2),
+  z.literal(3),
+])
 
 export const createFlowchartRequestSchema = z.object({
   problemId: z.number().int().positive(),
-  mermaidCode: z.string().trim().min(1).max(50_000).refine(
-    (value) => value.split("\n").filter((line) => line.trim()).length <= 200,
-    "Flowchart is too complex",
-  ),
+  mermaidCode: z
+    .string()
+    .trim()
+    .min(1)
+    .max(50_000)
+    .refine(
+      (value) => value.split("\n").filter((line) => line.trim()).length <= 200,
+      "Flowchart is too complex",
+    ),
   flowchartData: z.record(z.string(), z.unknown()).default({}),
 })
 
@@ -49,9 +59,19 @@ export const flowchartListItemSchema = z.object({
 })
 
 export const flowchartListSchema = paginatedSchema(flowchartListItemSchema)
-export const createFlowchartResponseSchema = z.object({ submissionId: z.string(), status: z.literal("pending") })
-export const flowchartCurrentSchema = z.object({ count: z.number().int(), score: z.number(), grade: z.string() })
-export const flowchartDetailSchema = z.object({ submission: flowchartSubmissionSchema.nullable(), count: z.number().int() })
+export const createFlowchartResponseSchema = z.object({
+  submissionId: z.string(),
+  status: z.literal("pending"),
+})
+export const flowchartCurrentSchema = z.object({
+  count: z.number().int(),
+  score: z.number(),
+  grade: z.string(),
+})
+export const flowchartDetailSchema = z.object({
+  submission: flowchartSubmissionSchema.nullable(),
+  count: z.number().int(),
+})
 
 export const flowchartStatisticsSchema = z.object({
   totalCount: z.number().int(),
@@ -94,7 +114,11 @@ export type FlowchartListItem = z.infer<typeof flowchartListItemSchema>
 export type FlowchartList = z.infer<typeof flowchartListSchema>
 export type FlowchartCurrent = z.infer<typeof flowchartCurrentSchema>
 export type FlowchartDetail = z.infer<typeof flowchartDetailSchema>
-export type CreateFlowchartResponse = z.infer<typeof createFlowchartResponseSchema>
-export type CreateFlowchartRequest = z.infer<typeof createFlowchartRequestSchema>
+export type CreateFlowchartResponse = z.infer<
+  typeof createFlowchartResponseSchema
+>
+export type CreateFlowchartRequest = z.infer<
+  typeof createFlowchartRequestSchema
+>
 
 export type FlowchartStatus = z.infer<typeof flowchartStatusSchema>