chore: batch commit remaining changes

Includes search engine improvements, Alembic migrations,
new services (pubmed_daily_update, query_expansion),
frontend updates, and documentation sync.

frontend/src/composables/useSearchHistory.ts

@@ -0,0 +1,113 @@
+import { ref } from 'vue'
+
+const STORAGE_KEY = 'pub_search_history'
+const MAX_ENTRIES = 50
+
+export interface HistoryEntry {
+  id: string
+  query: string
+  expanded_query: string
+  result_count: number | null
+  timestamp: string
+}
+
+function loadAll(): HistoryEntry[] {
+  try {
+    const raw = localStorage.getItem(STORAGE_KEY)
+    return raw ? JSON.parse(raw) : []
+  } catch {
+    return []
+  }
+}
+
+function saveAll(entries: HistoryEntry[]) {
+  localStorage.setItem(STORAGE_KEY, JSON.stringify(entries))
+}
+
+/** 把 #N 引用替换为 expanded_query（加括号保护优先级） */
+export function resolveQuery(query: string, entries: HistoryEntry[]): string {
+  return query.replace(/#(\d+)/g, (_m, num) => {
+    const found = entries.find(e => e.id === `#${num}`)
+    return found ? `(${found.expanded_query})` : _m
+  })
+}
+
+/** 递归展开所有 #N 引用为纯查询 */
+export function expandQuery(query: string, entries: HistoryEntry[]): string {
+  let prev = ''
+  let current = query
+  for (let i = 0; i < 10; i++) {
+    if (current === prev) break
+    prev = current
+    current = resolveQuery(current, entries)
+  }
+  return current
+}
+
+export function useSearchHistory() {
+  const entries = ref<HistoryEntry[]>(loadAll())
+
+  function getAll(): HistoryEntry[] {
+    return [...entries.value]
+  }
+
+  function add(query: string, resultCount?: number | null): HistoryEntry {
+    const all = loadAll()
+    const nextNum = all.length > 0
+      ? Math.max(...all.map(e => parseInt(e.id.slice(1), 10))) + 1
+      : 1
+    const id = `#${nextNum}`
+    const expanded = expandQuery(query, all)
+    const entry: HistoryEntry = {
+      id,
+      query,
+      expanded_query: expanded,
+      result_count: resultCount ?? null,
+      timestamp: new Date().toISOString(),
+    }
+
+    if (all.length >= MAX_ENTRIES) {
+      all.sort((a, b) => a.timestamp.localeCompare(b.timestamp))
+      all.shift()
+    }
+
+    all.push(entry)
+    saveAll(all)
+    entries.value = [...all]
+    return entry
+  }
+
+  function remove(id: string) {
+    const all = loadAll().filter(e => e.id !== id)
+    saveAll(all)
+    entries.value = all
+  }
+
+  function clear() {
+    localStorage.removeItem(STORAGE_KEY)
+    entries.value = []
+  }
+
+  function download() {
+    const all = loadAll()
+    const lines = all.map(e =>
+      `${e.id}\t${e.result_count ?? ''}\t${e.timestamp}\t${e.query}`
+    )
+    const blob = new Blob([lines.join('\n')], { type: 'text/plain;charset=utf-8' })
+    const url = URL.createObjectURL(blob)
+    const a = document.createElement('a')
+    a.href = url
+    a.download = `pubmed-search-history-${new Date().toISOString().slice(0, 10)}.tsv`
+    a.click()
+    URL.revokeObjectURL(url)
+  }
+
+  return {
+    entries,
+    getAll,
+    add,
+    remove,
+    clear,
+    download,
+  }
+}