fix: 第二轮PubMed搜索合规审计 — 8项修复 + 6项新测试

F1: search_engine.py `_pubmed_conditions` 顶层 [MH:noexp] 丢失 _noexp 标志
    按 _noexp 分组 mesh_terms，分别调用 _expand_mesh_tag_ids(noexp=True/False)

F2: search_engine.py 组内 NOT 违反 De Morgan 律
    全组 is_not=True 时单 NOT 包裹组合条件而非 per-term not_()

F3: pubmed_query_parser.py `_parse_not_expr` 不支持重复 NOT
    改为递归调用，NOT NOT toggle is_not（三重 NOT 正确）

F4: SearchView.vue Custom Range datePreset 不发送日期参数
    增加 datePreset === 'custom' 分支发送 year_from/year_to

F5: HomeView.vue restoreFromUrl 恢复不全
    补全 sort/field/retracted/negative_result

F6: AdvancedSearchPanel.vue precision_mode 死控件移除（UI+emit+reset）
    types/index.ts precision_mode 死类型字段移除

F7: types/index.ts is_oa 标记为 unused, reserved

F8: search_engine.py `_expand_mesh_tag_ids` N+1 → 2 批量查询
    所有 entry_terms 和 name_en 分别合并为 OR 查询

测试: 新增 NOT NOT/triple NOT/NOT group/DM:noexp 顶层 共 7 项

backend/app/services/pubmed_query_parser.py

@@ -227,6 +227,7 @@ class ParsedPubmedQuery:
     groups: list[list[Term]] = field(default_factory=list)         # parenthesized sub-groups
     group_operators: list[str] = field(default_factory=list)       # "and"/"or" per group (P2-2)
     negated_date_ranges: set[str] = field(default_factory=set)     # date fields negated by NOT
+    _date_range_markers: list[Term] = field(default_factory=list, repr=False)  # internal: date range Term collectors
 
 
 # ─── Parser ───
@@ -301,6 +302,12 @@ class PubmedQueryParser:
                     text = t.value.strip('"') if t.type == TokenType.QUOTED else t.value
                     result.plain_terms.append(Term(text=text, exact=(t.type == TokenType.QUOTED)))
 
+        # Recompute negated_date_ranges from marker terms (after NOT toggling from recursive _parse_not_expr)
+        result.negated_date_ranges = {
+            t.field.replace("__RANGE_", "").replace("__", "")
+            for t in result._date_range_markers if t.is_not
+        }
+
         return result
 
     def _dispatch_term(self, result: ParsedPubmedQuery, term: Term) -> None:
@@ -429,7 +436,10 @@ class PubmedQueryParser:
         """not_expr → NOT not_expr | primary"""
         if self.peek().type == TokenType.NOT:
             self.advance()
-            return self._parse_primary(result, negated=True)
+            inner = self._parse_not_expr(result)
+            for t in inner:
+                t.is_not = not t.is_not
+            return inner
         return self._parse_primary(result, negated=False)
 
     def _parse_primary(self, result: ParsedPubmedQuery, negated: bool = False) -> list[Term]:
@@ -541,6 +551,7 @@ class PubmedQueryParser:
                 setattr(result, date_attr_to, end_val)
             marker = Term(f"{start_val}:{end_val}", field=marker_field, is_not=negated)
             marker._is_range_end = True
+            result._date_range_markers.append(marker)
             if negated:
                 result.negated_date_ranges.add(field)
             return [marker]

backend/app/services/search_engine.py

@@ -636,18 +636,22 @@ class AdvancedSearchEngine:
                 else:
                     term_conditions.append(and_(*plain_conds) if len(plain_conds) > 1 else plain_conds[0])
 
-        # 3. [MH] → tree_number 展开，支持 is_not
+        # 3. [MH] → tree_number 展开，支持 is_not 和 _noexp
         if pp.mesh_terms:
-            pos_names = [t.text for t in pp.mesh_terms if not t.is_not]
-            neg_names = [t.text for t in pp.mesh_terms if t.is_not]
-            if pos_names:
-                cond = await AdvancedSearchEngine._expand_mesh_tag_ids(db, pos_names, major_only=False)
-                if cond is not None:
-                    term_conditions.append(cond)
-            if neg_names:
-                cond = await AdvancedSearchEngine._expand_mesh_tag_ids(db, neg_names, major_only=False)
-                if cond is not None:
-                    term_conditions.append(not_(cond))
+            for is_neg in (False, True):
+                subset = [t for t in pp.mesh_terms if t.is_not == is_neg]
+                if not subset:
+                    continue
+                noexp_names = [t.text for t in subset if t._noexp]
+                exp_names = [t.text for t in subset if not t._noexp]
+                if exp_names:
+                    cond = await AdvancedSearchEngine._expand_mesh_tag_ids(db, exp_names, major_only=False)
+                    if cond is not None:
+                        term_conditions.append(not_(cond) if is_neg else cond)
+                if noexp_names:
+                    cond = await AdvancedSearchEngine._expand_mesh_tag_ids(db, noexp_names, major_only=False, noexp=True)
+                    if cond is not None:
+                        term_conditions.append(not_(cond) if is_neg else cond)
 
         # 4. [MAJR] → tree_number 展开 + is_major=True，支持 is_not
         if pp.majr_terms:
@@ -862,19 +866,22 @@ class AdvancedSearchEngine:
         if pp.groups:
             for idx, group in enumerate(pp.groups):
                 group_conds = []
+                all_not = all(t.is_not for t in group)
                 for t in group:
                     cond = await AdvancedSearchEngine._single_term_condition(db, t)
                     if cond is not None:
-                        if t.is_not:
+                        if not all_not and t.is_not:
                             cond = not_(cond)
                         group_conds.append(cond)
                 if group_conds:
-                    # P2-2: 使用组内保留的布尔运算符
                     gop = (pp.group_operators[idx]
                            if idx < len(pp.group_operators)
                            else "and")
                     combine_fn = or_ if gop == "or" else and_
-                    term_conditions.append(combine_fn(*group_conds) if len(group_conds) > 1 else group_conds[0])
+                    combined = combine_fn(*group_conds) if len(group_conds) > 1 else group_conds[0]
+                    if all_not and len(group_conds) > 1:
+                        combined = not_(combined)
+                    term_conditions.append(combined)
 
         # 将 term_conditions 加入 conditions
         if term_conditions:
@@ -1116,27 +1123,36 @@ class AdvancedSearchEngine:
         import uuid as _uuid
         mesh_tag_ids: set[_uuid.UUID] = set()
 
+        # Batch all mesh name lookups — 2 queries instead of 2N
+        entry_conds = []
+        name_conds = []
         for m in mesh_names:
             q = m.strip().lower()
             if not q:
                 continue
-            # 1a. 精确入口词匹配（P1-3）
+            # 1a. 精确入口词匹配（P1-3）— batch via OR
+            entry_conds.append(GlobalTag.entry_terms.contains([q]))
+            # 1b. name_en ILIKE 回退 — batch via OR
+            name_conds.append(GlobalTag.name_en.ilike(m))
+
+        if entry_conds:
             rows = (await db.execute(
                 select(GlobalTag.id).where(
                     GlobalTag.source.in_(["mesh", "manual"]),
                     GlobalTag.mesh_ui.isnot(None),
                     GlobalTag.entry_terms.isnot(None),
-                    GlobalTag.entry_terms.contains([q]),
+                    or_(*entry_conds),
                 )
             )).all()
             for (tid,) in rows:
                 mesh_tag_ids.add(tid)
-            # 1b. name_en ILIKE 回退
+
+        if name_conds:
             rows = (await db.execute(
                 select(GlobalTag.id).where(
                     GlobalTag.source.in_(["mesh", "manual"]),
                     GlobalTag.mesh_ui.isnot(None),
-                    GlobalTag.name_en.ilike(m),
+                    or_(*name_conds),
                 )
             )).all()
             for (tid,) in rows:

backend/tests/test_comprehensive_verify.py

@@ -319,3 +319,50 @@ class TestNegatedTerms:
         jones = [t for t in r.author_terms if t.text == "Jones"]
         assert jones[0].is_not is True
         assert r.has_not is True
+
+    def test_not_not_cancels(self):
+        """NOT NOT cancer — double negation cancels out"""
+        r = parse_pubmed_query("NOT NOT cancer")
+        # cancer should be positive (NOT NOT X = X)
+        plain = [t for t in r.plain_terms if t.text == "cancer"]
+        assert len(plain) == 1
+        assert plain[0].is_not is False
+        # no literal "NOT" as search term
+        not_terms = [t for t in r.plain_terms if t.text.upper() == "NOT"]
+        assert len(not_terms) == 0, f"Second NOT should not be a literal term: {r.plain_terms}"
+
+    def test_not_not_date_range(self):
+        """NOT NOT 2024:2025[DP] — double negation on date range"""
+        r = parse_pubmed_query("NOT NOT 2024:2025[DP]")
+        # After double NOT, the date range should NOT be negated
+        assert "DP" not in r.negated_date_ranges, f"negated_date_ranges={r.negated_date_ranges}"
+
+    def test_mh_noexp_top_level(self):
+        """asthma[MH:noexp] at top level should preserve _noexp flag"""
+        r = parse_pubmed_query("asthma[MH:noexp]")
+        assert len(r.mesh_terms) == 1
+        assert r.mesh_terms[0]._noexp is True
+        assert r.mesh_terms[0].field == "MH"
+
+    def test_not_group_and(self):
+        """NOT (cancer AND tumor) — group NOT should set all terms is_not"""
+        r = parse_pubmed_query("NOT (cancer AND tumor)")
+        assert len(r.groups) >= 1
+        for group in r.groups:
+            for term in group:
+                assert term.is_not is True, f"All terms in negated group should be NOT: {group}"
+
+    def test_not_group_or(self):
+        """NOT (cancer OR tumor) — group NOT with OR"""
+        r = parse_pubmed_query("NOT (cancer OR tumor)")
+        assert len(r.groups) >= 1
+        for group in r.groups:
+            for term in group:
+                assert term.is_not is True
+
+    def test_triple_not(self):
+        """NOT NOT NOT cancer = NOT cancer"""
+        r = parse_pubmed_query("NOT NOT NOT cancer")
+        plain = [t for t in r.plain_terms if t.text == "cancer"]
+        assert len(plain) == 1
+        assert plain[0].is_not is True  # odd count = negated