HEL-202: 基于 b27016d 返工起算日/期初/断档并补齐公司端

以 deploy/hel178 为基线整合 HEL-200 内核：迁移改为 0008 复用
system_settings；修复确认批次 list>int、截止日当天漏算与持久化断言；
公司端余额完整/降级口径与断档说明、管理端审核界面接线。

Co-authored-by: Cursor <cursoragent@cursor.com>
Co-authored-by: multica-agent <github@multica.ai>

src/bank_importer/company_transfers.py

@@ -20,7 +20,7 @@ from decimal import Decimal, InvalidOperation
 import re
 import sqlite3
 
-from . import matching, settings
+from . import calculation, matching, settings
 
 _DATE_RE = re.compile(r"^\d{4}-\d{2}-\d{2}$")
 _ZERO = Decimal("0.00")
@@ -72,7 +72,8 @@ def _window_bounds(
     connection: sqlite3.Connection, as_of: str | None
 ) -> tuple[str, str]:
     end = _validate_date(as_of, "as_of") if as_of else today_shanghai()
-    start = settings.get_settings(connection).get("start_date") or "2026-01-01"
+    calc_start = calculation.get_calculation_start_date(connection)
+    start = calc_start or settings.get_settings(connection).get("start_date") or "2026-01-01"
     start = _validate_date(start, "start_date")
     if start > end:
         # Opening / start-date plumbing may lag; clamp rather than 500.
@@ -282,15 +283,28 @@ def company_intercompany_summary(
             }
         )
 
+    # Enrich window with calculation-basis opening/ending when configured.
+    balances = calculation.compute_company_balances(
+        connection, company_id, cutoff=end
+    )
+    has_opening = balances.get("basis") == "full"
+    opening_total = _ZERO
+    ending_total = _ZERO
+    if has_opening:
+        for pair in balances.get("pairs") or []:
+            opening_total += _as_decimal(pair.get("opening") or "0")
+            ending_total += _as_decimal(pair.get("closing") or "0")
+
     return {
         "own_company": own,
         "window": {
             "start": start,
             "end": end,
-            "has_opening": False,
-            # Reserved for opening-balance rollout; callers must not invent balances.
-            "opening": None,
-            "ending": None,
+            "has_opening": has_opening,
+            "opening": _money(opening_total) if has_opening else None,
+            "ending": _money(ending_total) if has_opening else None,
+            "basis": balances.get("basis"),
+            "calculation_start_date": balances.get("calculation_start_date"),
         },
         "confirmed": {
             "outflow_total": _money(outflow),