fix: backtest equity curve bugs (#39)

- Fix SELL logic: correctly reduce position.quantity after selling (core bug)
  Previously positions were never decremented, causing sold positions to be
  settled again at backtest end, inflating final balance.
- Fix settleRemainingPositions: profitLoss now correctly computes
  settlementValue - cost (was incorrectly using settlementValue.negate())
- Fix max drawdown calculation: use current balance instead of previous
  iteration's runningBalance
- Frontend: add comment noting chart shows cash balance, not total equity

.github/ISSUE_TEMPLATE/ai-bug-report.yml

@@ -0,0 +1,183 @@
+---
+name: 🤖 Bug Report for AI Fix / AI Bug 报告
+description: Bug 报告模板
+title: '[Bug] / '
+assignees: []
+body:
+  - type: markdown
+    attributes:
+      value: |
+        ## Bug Report Template 🐛
+
+        本模板用于报告 PolyHermes 项目的 bug。
+
+        ⚠️ **Important / 重要提示**：
+        - AI fixes will be on the `fix_issues_by_ai` branch / AI 修复将在 `fix_issues_by_ai` 分支上进行
+        - All AI fixes require human review before merging / 所有 AI 修复需要人工审核后才能合并
+        - Security vulnerabilities, database migrations, major changes are not recommended for AI auto-fix
+          / 涉及安全漏洞、数据库迁移、重大变更等问题不建议使用 AI 自动修复
+
+        ---
+        
+        本模板用于报告 PolyHermes 项目的 bug。
+
+        This template is for reporting bugs in the PolyHermes project.
+
+  - type: textarea
+    id: description
+    attributes:
+      label: 📝 Bug Description / Bug 描述
+      description: Clearly and concisely describe the bug / 清晰简洁地描述这个 bug
+      placeholder: Describe the bug you encountered / 描述你遇到的问题...
+    validations:
+      required: true
+
+  - type: dropdown
+    id: type
+    attributes:
+      label: 🎯 Bug Type / 问题类型
+      description: Select the type of bug / 选择问题类型
+      options:
+        - Frontend bug (UI/UX/interaction) / 前端 bug (UI/UX/交互问题)
+        - Backend bug (API/logic/data) / 后端 bug (API/逻辑/数据处理)
+        - Database issue / 数据库问题
+        - Performance issue / 性能问题
+        - Configuration/Deployment / 配置/部署问题
+        - Documentation / 文档问题
+        - Other / 其他
+    validations:
+      required: true
+
+  - type: dropdown
+    id: scope
+    attributes:
+      label: 📍 Affected Scope / 影响范围
+      description: Select the scope of impact / 选择问题影响范围
+      options:
+        - Specific page/function only / 仅影响特定页面/功能
+        - Entire system / 影响整个系统
+        - Specific user role / 影响特定用户角色
+        - Only in specific environment / 仅在特定环境下重现
+    validations:
+      required: true
+
+  - type: textarea
+    id: steps
+    attributes:
+      label: 🔍 Steps to Reproduce / 复现步骤
+      description: Provide clear, detailed steps to reproduce the bug / 提供清晰、详细的步骤来重现这个 bug
+      placeholder: |
+        1. Visit page: `...` / 访问页面：`...`
+        2. Click button: `...` / 点击按钮：`...`
+        3. Input data: `...` / 输入数据：`...`
+        4. Submit form: `...` / 提交表单：`...`
+        5. Observe error: `...` / 观察到错误：`...`
+    validations:
+      required: true
+
+  - type: dropdown
+    id: frequency
+    attributes:
+      label: Reproduction Frequency / 复现频率
+      options:
+        - Always reproducible (100%) / 总是能复现 (100%)
+        - Frequently reproducible (50%+) / 经常能复现 (50%+)
+        - Occasionally reproducible (<50%) / 偶尔能复现 (<50%)
+        - Hard to reproduce / 很难复现
+    validations:
+      required: true
+
+  - type: textarea
+    id: expected
+    attributes:
+      label: 💻 Expected Behavior / 预期行为
+      description: Describe what you expected to happen / 描述你期望发生什么
+      placeholder: What should happen / 应该发生什么...
+    validations:
+      required: true
+
+  - type: textarea
+    id: actual
+    attributes:
+      label: ❌ Actual Behavior / 实际行为
+      description: Describe what actually happened / 描述实际发生了什么
+      placeholder: What actually happened / 实际发生了什么...
+    validations:
+      required: true
+
+  - type: textarea
+    id: screenshots
+    attributes:
+      label: 📸 Screenshots / Recordings / 截图/录屏
+      description: If applicable, add screenshots or recordings to illustrate the problem (drag and drop files here)
+        / 如果适用，添加截图或录屏来说明问题（可以拖拽文件到这里）
+      placeholder: Add screenshots or recordings / 添加截图或录屏...
+
+  - type: textarea
+    id: environment
+    attributes:
+      label: 🌐 Environment / 环境
+      description: Provide relevant environment information / 提供相关环境信息
+      value: |
+        **Browser (for frontend issues) / 浏览器（前端问题）：**
+        - Browser: ______ / 浏览器：______
+        - Browser version: ______ / 浏览器版本：______
+        - Operating System: ______ / 操作系统：______
+
+        **Backend Environment (for backend issues) / 后端环境（后端问题）：**
+        - Node.js version: ______ / Node.js 版本：______
+        - Database version: ______ / 数据库版本：______
+        - Docker version (if used): ______ / Docker 版本（如果使用）：______
+        - Other relevant dependencies: ______ / 其他相关依赖版本：______
+    validations:
+      required: false
+
+  - type: textarea
+    id: related-files
+    attributes:
+      label: 📁 Related Files / Code / 相关文件/代码
+      description: Provide relevant file paths or code snippets / 提供可能涉及的文件路径或相关代码片段
+      placeholder: |
+        Possibly related files / 可能涉及的文件：
+        - frontend/src/components/...
+        - backend/src/main/kotlin/...
+
+        Error logs / 错误日志：
+        ```
+        Paste error logs here / 粘贴错误日志
+        ```
+    validations:
+      required: false
+
+  - type: textarea
+    id: suggestions
+    attributes:
+      label: 🎯 Fix Suggestions (Optional) / 修复建议（可选）
+      description: If you have fix ideas, describe them briefly / 如果你有修复思路，可以在这里简单描述
+      placeholder: |
+        Suggest adding ZZZ check in the YYY method of file XXX
+        / 建议在 XXX 文件的 YYY 方法中，添加 ZZZ 检查
+        ...
+
+  - type: dropdown
+    id: priority
+    attributes:
+      label: 🚨 Priority / 优先级
+      options:
+        - 🔴 High - Blocking core functionality, affects user experience / 高 - 阻塞核心功能，影响用户体验
+        - 🟡 Medium - Limited functionality but not blocking / 中 - 功能受限但不阻塞
+        - 🟢 Low - Minor issue, doesn't affect usage / 低 - 小问题，不影响使用
+    validations:
+      required: true
+
+  - type: textarea
+    id: additional
+    attributes:
+      label: 📝 Additional Information / 补充说明
+      description: Any other information that helps AI understand and fix the issue / 任何其他有助于 AI 理解和修复问题的信息
+      placeholder: |
+        - Was this bug introduced recently? / 这个 bug 是最近引入的吗？
+        - Is it related to a specific PR or commit? / 是否与某个特定的 PR 或 commit 相关？
+        - Does it only occur with specific datasets or users? / 是否只在特定数据集或特定用户情况下出现？
+        / ...
+        Any other context / 其他任何上下文信息...

.github/workflows/close-issue-on-pr-merge.yml

@@ -0,0 +1,127 @@
+# PR 合并后自动关闭关联的 Issue
+# 当 PR 从 ai_fix/N_xxx 分支合并到 main 时，关闭 #N 对应的 Issue（若 PR 描述中未含 Closes #N 则通过分支名解析）
+# 关闭后发送 Telegram 通知（复用 TELEGRAM_BOT_TOKEN / TELEGRAM_CHAT_ID）
+
+name: Close issue on PR merge
+
+on:
+  pull_request:
+    types: [closed]
+    branches: [main]
+
+jobs:
+  close-issue:
+    if: github.event.pull_request.merged == true
+    runs-on: ubuntu-latest
+    permissions:
+      issues: write
+      pull-requests: read
+
+    steps:
+      - name: Get PR info
+        id: pr
+        run: |
+          # 从 PR body 查找 Closes #N / Fixes #N（若已有则 GitHub 已自动关 issue，本 step 仅做解析）
+          BODY="${{ github.event.pull_request.body }}"
+          HEAD_REF="${{ github.event.pull_request.head.ref }}"
+
+          # 优先从 PR 描述解析（无匹配时 grep 会 exit 1，需 || true 避免 set -e 导致脚本退出）
+          ISSUE_NUM=$(echo "$BODY" | grep -oE '(Closes|Fixes|Resolves) #([0-9]+)' | head -1 | grep -oE '[0-9]+' || true)
+          if [ -z "$ISSUE_NUM" ]; then
+            # 从分支名解析 ai_fix/N_xxx
+            ISSUE_NUM=$(echo "$HEAD_REF" | sed -n 's|^ai_fix/\([0-9]*\)_.*|\1|p')
+          fi
+
+          if [ -z "$ISSUE_NUM" ]; then
+            echo "ISSUE_NUMBER=" >> $GITHUB_OUTPUT
+            echo "skip=true" >> $GITHUB_OUTPUT
+            echo "未从 PR 描述或分支名解析到 Issue 编号，跳过关闭"
+            exit 0
+          fi
+
+          echo "ISSUE_NUMBER=$ISSUE_NUM" >> $GITHUB_OUTPUT
+          echo "skip=false" >> $GITHUB_OUTPUT
+          echo "解析到 Issue #$ISSUE_NUM"
+
+      - name: Get issue details
+        if: steps.pr.outputs.skip != 'true'
+        id: issue
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          ISSUE_NUM="${{ steps.pr.outputs.ISSUE_NUMBER }}"
+          # 获取 issue 标题与 URL（用于 TG 消息）
+          JSON=$(gh issue view "$ISSUE_NUM" --json title,url 2>/dev/null || echo '{"title":"","url":""}')
+          TITLE=$(echo "$JSON" | jq -r '.title')
+          ISSUE_URL=$(echo "$JSON" | jq -r '.url')
+          echo "title<<EOF" >> $GITHUB_OUTPUT
+          echo "$TITLE" >> $GITHUB_OUTPUT
+          echo "EOF" >> $GITHUB_OUTPUT
+          echo "url=$ISSUE_URL" >> $GITHUB_OUTPUT
+
+      - name: Close issue
+        if: steps.pr.outputs.skip != 'true'
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const issueNumber = parseInt('${{ steps.pr.outputs.ISSUE_NUMBER }}', 10);
+            if (!issueNumber || isNaN(issueNumber)) {
+              console.log('No valid issue number, skip');
+              return;
+            }
+            const { data: issue } = await github.rest.issues.get({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: issueNumber
+            });
+            if (issue.state === 'open') {
+              await github.rest.issues.update({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                issue_number: issueNumber,
+                state: 'closed'
+              });
+              console.log(`Issue #${issueNumber} closed.`);
+            } else {
+              console.log(`Issue #${issueNumber} already closed.`);
+            }
+
+      - name: Send Telegram notification
+        if: steps.pr.outputs.skip != 'true'
+        env:
+          TELEGRAM_BOT_TOKEN: ${{ secrets.TELEGRAM_BOT_TOKEN }}
+          TELEGRAM_CHAT_ID: ${{ secrets.TELEGRAM_CHAT_ID }}
+        run: |
+          # 与 docker-build 一致：未配置则跳过
+          if [ -z "$TELEGRAM_BOT_TOKEN" ] || [ -z "$TELEGRAM_CHAT_ID" ]; then
+            echo "⚠️  Telegram Bot Token 或 Chat ID 未配置，跳过通知"
+            exit 0
+          fi
+
+          ISSUE_NUM="${{ steps.pr.outputs.ISSUE_NUMBER }}"
+          ISSUE_TITLE="${{ steps.issue.outputs.title }}"
+          ISSUE_URL="${{ steps.issue.outputs.url }}"
+          PR_URL="${{ github.event.pull_request.html_url }}"
+
+          # 与 docker-build 相同的 HTML 消息格式
+          MESSAGE="✅ <b>AI 修复的 Issue 已关闭</b>"$'\n'$'\n'"🔢 <b>Issue:</b> #${ISSUE_NUM} ${ISSUE_TITLE}"$'\n'"📎 <a href=\"${ISSUE_URL}\">查看 Issue</a>"$'\n'"🔗 <a href=\"${PR_URL}\">查看 PR</a>"
+
+          curl -s -X POST "https://api.telegram.org/bot${TELEGRAM_BOT_TOKEN}/sendMessage" \
+            -H "Content-Type: application/json" \
+            -d "$(jq -n \
+              --arg chat_id "$TELEGRAM_CHAT_ID" \
+              --arg text "$MESSAGE" \
+              '{chat_id: $chat_id, text: $text, parse_mode: "HTML", disable_web_page_preview: false}')" > /tmp/telegram_response.json
+
+          if [ $? -eq 0 ]; then
+            RESPONSE=$(cat /tmp/telegram_response.json)
+            if echo "$RESPONSE" | grep -q '"ok":true'; then
+              echo "✅ Telegram 通知发送成功"
+            else
+              echo "❌ Telegram 通知发送失败: $RESPONSE"
+              exit 0
+            fi
+          else
+            echo "❌ 发送 Telegram 消息时发生错误"
+            exit 0
+          fi

backend/src/main/kotlin/com/wrbug/polymarketbot/service/backtest/BacktestExecutionService.kt

@@ -408,10 +408,25 @@ class BacktestExecutionService(
                                 val cost = actualSellQuantity.multiply(position.avgPrice)
                                 val profitLoss = netAmount.subtract(cost)
 
-                                // 更新余额和持仓
+                                // Bug #39 Fix: correctly reduce position quantity after sell
                                 currentBalance += netAmount
-                                if (position.quantity <= BigDecimal.ZERO) {
+                                val remainingQuantity = position.quantity - actualSellQuantity
+                                val remainingLeaderBuyQuantity = if (position.leaderBuyQuantity != null && position.leaderBuyQuantity > BigDecimal.ZERO) {
+                                    val totalQty = position.quantity
+                                    val leaderReduction = actualSellQuantity.divide(
+                                        totalQty, 8, java.math.RoundingMode.DOWN
+                                    )
+                                    (position.leaderBuyQuantity - leaderReduction).coerceAtLeast(BigDecimal.ZERO)
+                                } else {
+                                    position.leaderBuyQuantity
+                                }
+                                if (remainingQuantity <= BigDecimal.ZERO) {
                                     positions.remove(positionKey)
+                                } else {
+                                    positions[positionKey] = position.copy(
+                                        quantity = remainingQuantity,
+                                        leaderBuyQuantity = remainingLeaderBuyQuantity
+                                    )
                                 }
 
                                 // 记录交易到当前页列表
@@ -632,7 +647,8 @@ class BacktestExecutionService(
             val settlementPrice = avgPrice
 
             val settlementValue = quantity.multiply(settlementPrice)
-            val profitLoss = settlementValue.negate()
+            // Bug #39 Fix: profitLoss for closed settlement at avgPrice should be ~0
+            val profitLoss = settlementValue.subtract(quantity.multiply(avgPrice))
 
             balance += settlementValue
 
@@ -702,7 +718,8 @@ class BacktestExecutionService(
             if (balance > peakBalance) {
                 peakBalance = balance
             }
-            val drawdown = peakBalance - runningBalance
+            // Bug #39 Fix: use current balance, not runningBalance from previous iteration
+            val drawdown = peakBalance - balance
             if (drawdown > maxDrawdown) {
                 maxDrawdown = drawdown
             }

backend/src/main/kotlin/com/wrbug/polymarketbot/service/cryptotail/CryptoTailStrategyExecutionService.kt

@@ -43,6 +43,9 @@ private const val SPREAD_MAX_PRICE_ADJUSTMENT = "0.02"
 /** 数量小数位数，与 OrderSigningService 的 roundConfig.size 一致 */
 private const val SIZE_DECIMAL_SCALE = 2
 
+/** 单笔下单最小 USDC 金额（平台限制），RATIO 模式计算值低于此值时按此值下单 */
+private val MIN_ORDER_USDC = BigDecimal("1")
+
 /**
  * 周期内预置上下文：账户、解密凭证、费率、签名类型、CLOB 客户端；不含预签订单。
  * 触发时 FIXED/RATIO 均按 outcomeIndex 计算 size 并签名提交。
@@ -151,7 +154,7 @@ class CryptoTailStrategyExecutionService(
         }
         val signatureType = orderSigningService.getSignatureTypeForWalletType(account.walletType)
 
-        if (strategy.amountMode.uppercase() != "RATIO" && strategy.amountValue < BigDecimal("1")) return null
+        if (strategy.amountMode.uppercase() != "RATIO" && strategy.amountValue < MIN_ORDER_USDC) return null
 
         val ctx = PeriodContext(
             strategy = strategy,
@@ -334,29 +337,36 @@ class CryptoTailStrategyExecutionService(
         val ctx = getOrInvalidatePeriodContext(strategy, periodStartUnix)
 
         if (ctx != null) {
-            val amountUsdc = when (strategy.amountMode.uppercase()) {
+            var availableBalanceForRatio = BigDecimal.ZERO
+            var amountUsdc = when (strategy.amountMode.uppercase()) {
                 "RATIO" -> {
                     val balanceResult = accountService.getAccountBalance(ctx.account.id)
                     val availableBalance =
                         balanceResult.getOrNull()?.availableBalance?.toSafeBigDecimal() ?: BigDecimal.ZERO
+                    availableBalanceForRatio = availableBalance
                     availableBalance.multiply(strategy.amountValue).divide(BigDecimal("100"), 18, RoundingMode.DOWN)
                 }
 
                 else -> strategy.amountValue
             }
-            if (amountUsdc < BigDecimal("1")) {
-                saveTriggerRecord(
-                    strategy,
-                    periodStartUnix,
-                    marketTitle,
-                    outcomeIndex,
-                    triggerPrice,
-                    amountUsdc,
-                    null,
-                    "fail",
-                    "投入金额不足"
-                )
-                return
+            if (amountUsdc < MIN_ORDER_USDC) {
+                val amountMode = strategy.amountMode.uppercase()
+                if (amountMode == "RATIO" && availableBalanceForRatio >= MIN_ORDER_USDC) {
+                    amountUsdc = MIN_ORDER_USDC
+                } else {
+                    saveTriggerRecord(
+                        strategy,
+                        periodStartUnix,
+                        marketTitle,
+                        outcomeIndex,
+                        triggerPrice,
+                        amountUsdc,
+                        null,
+                        "fail",
+                        "投入金额不足"
+                    )
+                    return
+                }
             }
 
             val tokenId = tokenIds.getOrNull(outcomeIndex) ?: run {
@@ -514,23 +524,28 @@ class CryptoTailStrategyExecutionService(
 
         val balanceResult = accountService.getAccountBalance(account.id)
         val availableBalance = balanceResult.getOrNull()?.availableBalance?.toSafeBigDecimal() ?: BigDecimal.ZERO
-        val amountUsdc = when (strategy.amountMode.uppercase()) {
+        var amountUsdc = when (strategy.amountMode.uppercase()) {
             "RATIO" -> availableBalance.multiply(strategy.amountValue).divide(BigDecimal("100"), 18, RoundingMode.DOWN)
             else -> strategy.amountValue
         }
-        if (amountUsdc < BigDecimal("1")) {
-            saveTriggerRecord(
-                strategy,
-                periodStartUnix,
-                marketTitle,
-                outcomeIndex,
-                triggerPrice,
-                amountUsdc,
-                null,
-                "fail",
-                "投入金额不足"
-            )
-            return
+        if (amountUsdc < MIN_ORDER_USDC) {
+            val amountMode = strategy.amountMode.uppercase()
+            if (amountMode == "RATIO" && availableBalance >= MIN_ORDER_USDC) {
+                amountUsdc = MIN_ORDER_USDC
+            } else {
+                saveTriggerRecord(
+                    strategy,
+                    periodStartUnix,
+                    marketTitle,
+                    outcomeIndex,
+                    triggerPrice,
+                    amountUsdc,
+                    null,
+                    "fail",
+                    "投入金额不足"
+                )
+                return
+            }
         }
 
         val tokenId = tokenIds.getOrNull(outcomeIndex) ?: run {

frontend/src/pages/BacktestChart.tsx

@@ -10,6 +10,8 @@ interface BacktestChartProps {
   }[]
 }
 
+// Bug #39 Note: This chart currently displays cash balance (balanceAfter), not total equity.
+// A true equity curve (cash + position value) would require an equityAfter field in the trade records.
 const BacktestChart: React.FC<BacktestChartProps> = ({ trades }) => {
   const { t } = useTranslation()
   const chartRef = useRef<HTMLDivElement>(null)