B-44: intercompany ledger events, subject review and drill-down evidence

- migration 6: manual_records, ledger_event_revisions chain, current
  projections, source claims, subject suggestions, eligible_position_events
- ledger_events.py: bank-event reconciliation, reversal/adjustment/reopen,
  append-only revision chain and rebuildable current projection
- subjects.py: fixed subject mirror, draft suggestion dictionary, explicit
  administrator subject confirmation with expected_revision + idempotency
- manual_records.py: submit, approve new/link, return/exception/reverse,
  candidate hints, idempotent replay and concurrency-safe claims
- positions.py: Decimal aggregation, both-perspective conservation asserts,
  cutoff window, unresolved gross buckets, keyset pagination, evidence
  visibility (visible/masked/missing)
- server.py: admin + company intercompany APIs with tenant isolation (404 on
  cross-tenant reads, 403 on company writes) and auto reconcile wiring
- admin/company portals: balance directory, pair drill-down drawer, evidence
  drawer, subject/manual audit queue, company balance summary
- tests: ledger events, subjects, manual records, positions, HTTP API and
  migration persistence (233 total, all green)

web/company.html

@@ -26,7 +26,8 @@
           <button class="nav-item" data-view="upload"><svg><use href="icons.svg#upload"/></svg><span>流水导入</span></button>
           <button class="nav-item" data-view="manual"><svg><use href="icons.svg#plus"/></svg><span>手工记录</span></button>
           <button class="nav-item" data-view="flows"><svg><use href="icons.svg#file-spreadsheet"/></svg><span>流水管理</span></button>
-          <button class="nav-item" data-view="reconcile"><svg><use href="icons.svg#arrow-left-right"/></svg><span>往来确认</span><b>2</b></button>
+          <button class="nav-item" data-view="balances"><svg><use href="icons.svg#arrow-left-right"/></svg><span>往来余额</span></button>
+          <button class="nav-item" data-view="reconcile"><svg><use href="icons.svg#circle-check"/></svg><span>往来确认</span><b>2</b></button>
           <button class="nav-item" data-view="accounts"><svg><use href="icons.svg#landmark"/></svg><span>银行账户</span></button>
           <button class="nav-item" data-view="notifications"><svg><use href="icons.svg#bell"/></svg><span>通知</span><b>2</b></button>
         </nav>
@@ -140,7 +141,7 @@
                 <div class="form-body">
                   <div class="form-grid"><label class="field"><span>交易日期</span><input name="transactionDate" type="date" value="2026-08-06" required /></label><label class="field"><span>收付方向</span><select name="direction" required><option>付款</option><option>收款</option></select></label></div>
                   <div class="form-grid"><label class="field"><span>金额（元）</span><input name="amount" type="number" min="0.01" step="0.01" required /></label><label class="field"><span>资金来源</span><select name="sourceAccount" required><option value="">请选择</option><option>个人过账</option></select></label></div>
-                  <div class="form-grid"><label class="field"><span>对方类型</span><select name="counterpartyType" required><option>集团内部公司</option><option>个人过账方</option><option>外部单位</option></select></label><label class="field"><span>对方名称</span><input name="counterparty" maxlength="100" placeholder="公司全称或个人姓名" required /></label></div>
+                  <div class="form-grid"><label class="field"><span>对方类型</span><select name="counterpartyType" required><option>集团内部公司</option><option>个人过账方</option><option>外部单位</option></select></label><label class="field"><span>对方公司</span><select name="counterparty" required><option value="">请选择集团内部公司</option></select></label></div>
                   <div class="form-grid"><label class="field"><span>对方账号</span><input name="counterpartyAccount" maxlength="64" placeholder="可选" /></label><label class="field"><span>往来科目</span><select name="subject" required><option>应收</option><option>应付</option><option>其他应收</option><option>其他应付</option></select></label></div>
                   <label class="field"><span>业务摘要</span><input name="summary" maxlength="120" placeholder="例如：个人代付后转回" required /></label>
                   <label class="field"><span>补充说明</span><textarea name="remark" rows="3" maxlength="500" placeholder="说明形成原因和核对依据" required></textarea></label>
@@ -162,6 +163,25 @@
             <section class="panel"><div class="table-summary"><span>当前结果 <strong id="flowCount">3</strong> 笔</span><span>金额单位：元</span></div><div class="table-scroll"><table class="data-table" id="flowTable"><thead><tr><th>日期</th><th>银行账户</th><th>方向</th><th>对方户名 / 账号</th><th>摘要</th><th>银行流水号</th><th>归集状态</th><th class="number">金额</th></tr></thead><tbody><tr data-bank="中信银行"><td>2026.07.18</td><td>中信银行 · 5316</td><td>转出</td><td><strong>B公司</strong><small>尾号 9481</small></td><td>往来款</td><td>CIT260718018</td><td><span class="status success">双边匹配</span></td><td class="number">10,000,000.00</td></tr><tr data-bank="建设银行"><td>2026.07.12</td><td>建设银行 · 0845</td><td>转出</td><td><strong>A公司</strong><small>尾号 5316</small></td><td>同名账户调拨</td><td>CCB260712031</td><td><span class="status neutral">同公司调拨</span></td><td class="number">2,000,000.00</td></tr><tr data-bank="中信银行"><td>2026.07.06</td><td>中信银行 · 5316</td><td>转入</td><td><strong>B公司</strong><small>尾号 9481</small></td><td>归还往来款</td><td>CIT260706041</td><td><span class="status success">双边匹配</span></td><td class="number">3,200,000.00</td></tr></tbody></table></div></section>
           </section>
 
+          <section class="app-view" data-page="balances">
+            <header class="page-heading"><div><h1>往来余额</h1><p>本公司往来余额、对方公司明细与允许查看的源证据</p></div>
+              <span class="status neutral" id="companyOpeningNote">期初不可用 · 仅显示期间净变动</span>
+            </header>
+            <div class="company-alert balance-alert" id="companyUnresolvedAlert" hidden>
+              <svg><use href="icons.svg#circle-alert"/></svg>
+              <div><strong id="companyUnresolvedText"></strong><p>未确认事项不影响已确认余额，处理前请先核对证据。</p></div>
+              <button class="button secondary" data-view-link="reconcile">去确认</button>
+            </div>
+            <section class="pair-report" id="companyBalanceSummary">
+              <header class="pair-report-heading"><div><h2>本公司往来汇总</h2><p id="companyBalancePeriod">统计口径</p></div></header>
+              <div class="pair-balance-line is-six" id="companyBalanceLine"></div>
+            </section>
+            <section class="panel company-stack-panel">
+              <div class="panel-heading"><div><h2>对方公司明细</h2><p>点击任意对方公司查看往来事件与允许的源证据</p></div></div>
+              <div class="company-list" id="companyCounterparties" aria-live="polite"></div>
+            </section>
+          </section>
+
           <section class="app-view" data-page="reconcile">
             <header class="page-heading"><div><h1>往来确认</h1><p>系统计算为主，只处理无法确定的匹配与科目</p></div></header>
             <section class="reconcile-summary"><div><span>自动确认</span><strong>18 笔</strong><small>无需人工处理</small></div><div><span>单边待匹配</span><strong id="matchPendingCount">1 笔</strong><small>需选择对方证据</small></div><div><span>科目待确认</span><strong id="subjectPendingCount">1 笔</strong><small>需选择会计科目</small></div></section>
@@ -195,6 +215,17 @@
         <footer><button type="button" class="button secondary" data-close-account>取消</button><button class="button primary" type="submit">提交登记</button></footer>
       </form>
     </dialog>
+    <div class="drawer-scrim" id="drawerScrim" data-close-drawer aria-hidden="true"></div>
+    <aside class="drawer" id="evidenceDrawer" aria-label="往来明细与源行证据抽屉" aria-hidden="true">
+      <header class="drawer-header">
+        <div>
+          <div class="drawer-breadcrumb" id="drawerBreadcrumb"></div>
+          <h2 id="drawerTitle">往来明细</h2>
+        </div>
+        <button type="button" class="icon-button" data-close-drawer aria-label="关闭抽屉" title="关闭"><svg><use href="icons.svg#x"/></svg></button>
+      </header>
+      <div class="drawer-body" id="drawerBody" tabindex="-1"></div>
+    </aside>
     <div class="toast-region" id="toastRegion" aria-live="polite"></div>
     <script src="app.js"></script>
   </body>