fix: 出题分配算法重构 + 20题模板 + 非技术人员模板

问题修复:
- Math.round 导致合计偏差（3题→4题，5题→6题等）
- 补充轮次破坏维度权重比例
- 各维度无题型比例控制

修正方案:
- floor + remainder 分配法，保证合计永远 = count
- 按weight降序分配余数，权重高的优先
- 不足时仅补充轮，但仍保持维度优先
- 补充轮日志记录各维度实际分配数

新增功能:
- 技术人员模板 20题 (PROMPT:30/LLM:30/IDE:20/DEV_PATTERN:20)
- 非技术人员模板 10题 (PROMPT:50/LLM:30/WORK_CAPABILITY:20)
  → 面向非技术角色，不考核IDE和开发范式
- 模板支持任意维度组合，可灵活配置

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

server/src/assessment/services/question-bank.service.ts

@@ -534,30 +534,59 @@ export class QuestionBankService {
 
     const usedIds = new Set<string>();
     const selected: QuestionBankItem[] = [];
-    let availableItems = [...allItems];
+    const selectedDetail: string[] = [];
 
     if (dimensionWeights && dimensionWeights.length > 0) {
+      // ── 按权重公平分配题数（floor + remainder，保证总和 = count）──
       const totalWeight = dimensionWeights.reduce((s, d) => s + d.weight, 0);
-      for (const dw of dimensionWeights) {
-        const dimName = dw.name as QuestionDimension;
-        const targetForDim = Math.round(count * dw.weight / totalWeight);
-        let pool = availableItems.filter(i => i.dimension === dimName && !usedIds.has(i.id));
+
+      // 第一轮: floor 分配
+      const targets: { dw: typeof dimensionWeights[0]; target: number; taken: number }[]
+        = dimensionWeights.map(dw => ({
+            dw,
+            target: Math.floor(count * dw.weight / totalWeight),
+            taken: 0,
+          }));
+
+      let allocated = targets.reduce((s, t) => s + t.target, 0);
+      // 第二轮: 按 weight 降序分配余数（保证总和 = count）
+      const remainder = count - allocated;
+      if (remainder > 0) {
+        const sortedByWeight = [...targets].sort((a, b) => b.dw.weight - a.dw.weight);
+        for (let i = 0; i < remainder; i++) {
+          sortedByWeight[i % sortedByWeight.length].target++;
+        }
+      }
+
+      // 各维度抽题
+      for (const t of targets) {
+        const dimName = t.dw.name as QuestionDimension;
+        let pool = allItems.filter(i => i.dimension === dimName && !usedIds.has(i.id));
         pool = this.shuffleArray(pool);
-        const take = Math.min(targetForDim, pool.length);
+        const take = Math.min(t.target, pool.length);
         for (let i = 0; i < take; i++) {
           selected.push(pool[i]);
           usedIds.add(pool[i].id);
+          t.taken++;
+        }
+        selectedDetail.push(`${dimName}: ${t.taken}/${t.target}`);
+      }
+
+      // 如果有维度出题不足，从其他维度补
+      if (selected.length < count) {
+        const remaining = allItems.filter(i => !usedIds.has(i.id));
+        const shuffled = this.shuffleArray(remaining);
+        for (const item of shuffled) {
+          if (selected.length >= count) break;
+          selected.push(item);
+          usedIds.add(item.id);
+          selectedDetail.push(`${item.dimension}(补)`);
         }
       }
-      availableItems = availableItems.filter(i => !usedIds.has(i.id));
-      availableItems = this.shuffleArray(availableItems);
-      while (selected.length < count && availableItems.length > 0) {
-        const item = availableItems.pop()!;
-        selected.push(item);
-        usedIds.add(item.id);
-      }
     } else {
+      // ── 无维度权重：轮询 DIMENSIONS 列表 ──
       let dimIdx = 0;
+      const availableItems = [...allItems];
       while (selected.length < count && availableItems.length > 0) {
         const dim = DIMENSIONS[dimIdx % DIMENSIONS.length];
         dimIdx++;
@@ -567,13 +596,13 @@ export class QuestionBankService {
           const item = pool[idx];
           selected.push(item);
           usedIds.add(item.id);
-          availableItems = availableItems.filter(i => i.id !== item.id);
+          availableItems.splice(availableItems.findIndex(i => i.id === item.id), 1);
         }
         if (dimIdx >= DIMENSIONS.length * 3) break;
       }
       if (selected.length < count && availableItems.length > 0) {
-        availableItems = this.shuffleArray(availableItems);
-        for (const item of availableItems) {
+        const shuffled = this.shuffleArray(availableItems);
+        for (const item of shuffled) {
           if (selected.length >= count) break;
           if (!usedIds.has(item.id)) {
             selected.push(item);
@@ -583,6 +612,7 @@ export class QuestionBankService {
       }
     }
 
+    // 最后兜底
     if (selected.length < count) {
       const remaining = allItems.filter((i) => !usedIds.has(i.id));
       const shuffled = remaining.sort(() => Math.random() - 0.5);
@@ -594,7 +624,7 @@ export class QuestionBankService {
     }
 
     this.logger.log(
-      `[selectQuestions] Selected ${selected.length} questions from bank ${bankId}`,
+      `[selectQuestions] Selected ${selected.length}/${count} questions from bank ${bankId} | ${selectedDetail.join(', ')}`,
     );
     return this.shuffleArray(selected);
   }