perf: optimize MCP server (O(1) auth, compact JSON, trashedAt fix) + memento-note performance (lazy loading, server-side filtering, XSS fixes, dead code removal, security hardening)

MCP Server:
- Fix validateApiKey: O(1) direct lookup by shortId instead of loading all keys
- Add trashedAt:null filter to ALL note queries (trashed notes leaked in results)
- Compact JSON output (~40% smaller responses)
- Bounded session cache (Map with MAX_SESSIONS=500) to prevent memory leaks
- PostgreSQL connection pooling (connection_limit=10)
- Rewrite all 22 tool descriptions in clear English
- Fix /sse fallback to proper 307 redirect

memento-note Performance:
- loading=lazy on all note images
- Split notebooksRefreshKey from global refreshKey (note CRUD no longer re-fetches notebooks)
- Remove searchKey from trash count deps (no re-fetch on every keystroke)
- Server-side notebookId filter in getAllNotes() (biggest win)
- Skip collaborator fetch for non-shared notes (eliminates N+1 API calls)
- next/dynamic for MarkdownContent + 4 modals (code-split remark/rehype/KaTeX)
- Memoize DOMPurify sanitize with useMemo

Security:
- XSS: DOMPurify sanitize in note-card and note-history-modal
- Auth anti-enumeration: uniform errors in auth.ts
- CRON_SECRET mandatory on cron endpoints
- Rate limiting on login (5 attempts/min per email)
- Centralized API auth helpers (requireAuth/requireAdmin)
- randomize-labels changed GET→POST
- Removed debug endpoints (/api/debug/config, /api/debug/test-chat)

Cleanup:
- Removed dead code: .backup-keep, settings-backup, fix-*.js, debug-theme, fix-labels route
- Removed sensitive console.error in auth.ts
- Ollama fetchWithTimeout (30s/60s AbortController)
- i18n: full Arabic translation, Farsi missing keys
- Masonry drag-and-drop fix (localOrderMap, cross-section block)
- Sidebar notebook tooltip on truncation

memento-note/components/notebooks-list.tsx

@@ -1,6 +1,6 @@
 'use client'
 
-import { useState, useCallback } from 'react'
+import { useState, useCallback, useRef } from 'react'
 import Link from 'next/link'
 import { usePathname, useRouter, useSearchParams } from 'next/navigation'
 import { cn } from '@/lib/utils'
@@ -18,6 +18,36 @@ import { useLabels } from '@/context/LabelContext'
 import { LabelManagementDialog } from '@/components/label-management-dialog'
 import { Notebook } from '@/lib/types'
 import { getNotebookIcon } from '@/lib/notebook-icon'
+import { Tooltip, TooltipContent, TooltipTrigger } from '@/components/ui/tooltip'
+
+function NotebookNameTooltip({ name, children }: { name: string; children: React.ReactNode }) {
+  const spanRef = useRef<HTMLSpanElement>(null)
+  const [isTruncated, setIsTruncated] = useState(false)
+
+  const checkTruncation = useCallback((node: HTMLSpanElement | null) => {
+    if (!node) return
+    setIsTruncated(node.scrollWidth > node.clientWidth)
+  }, [])
+
+  return (
+    <Tooltip open={isTruncated ? undefined : false}>
+      <TooltipTrigger asChild>
+        <span
+          ref={(el) => { spanRef.current = el; checkTruncation(el) }}
+          onMouseEnter={() => checkTruncation(spanRef.current)}
+          className="truncate min-w-0"
+        >
+          {children}
+        </span>
+      </TooltipTrigger>
+      {isTruncated && (
+        <TooltipContent side="right" className="max-w-[240px] break-words text-sm">
+          {name}
+        </TooltipContent>
+      )}
+    </Tooltip>
+  )
+}
 
 export function NotebooksList() {
   const pathname = usePathname()
@@ -152,12 +182,14 @@ export function NotebooksList() {
                         className={cn("w-5 h-5 flex-shrink-0 fill-current", !notebook.color && "text-primary dark:text-primary-foreground")}
                         style={notebook.color ? { color: notebook.color } : undefined}
                       />
-                      <span
-                        className={cn("text-[15px] font-medium tracking-wide truncate min-w-0", !notebook.color && "text-primary dark:text-primary-foreground")}
-                        style={notebook.color ? { color: notebook.color } : undefined}
-                      >
-                        {notebook.name}
-                      </span>
+                      <NotebookNameTooltip name={notebook.name}>
+                        <span
+                          className={cn("text-[15px] font-medium tracking-wide", !notebook.color && "text-primary dark:text-primary-foreground")}
+                          style={notebook.color ? { color: notebook.color } : undefined}
+                        >
+                          {notebook.name}
+                        </span>
+                      </NotebookNameTooltip>
                     </div>
                     <div className="flex items-center gap-1 flex-shrink-0">
                       {/* Actions menu for active notebook */}
@@ -241,7 +273,11 @@ export function NotebooksList() {
                     )}
                   >
                     <NotebookIcon className="w-5 h-5 flex-shrink-0" />
-                    <span className="text-[15px] font-medium tracking-wide truncate min-w-0 text-start">{notebook.name}</span>
+                    <NotebookNameTooltip name={notebook.name}>
+                      <span className="text-[15px] font-medium tracking-wide text-start">
+                        {notebook.name}
+                      </span>
+                    </NotebookNameTooltip>
                     {(notebook as any).notesCount > 0 && (
                       <span className="text-xs text-gray-400 ms-2 flex-shrink-0">({new Intl.NumberFormat(language).format((notebook as any).notesCount)})</span>
                     )}