Fix 11 bugs: restore crash, draft leak, email failures, memory leaks

Critical fixes:
- sanitizeLoadedHitStats/VisitorStats: restore full state shape so a
  snapshot restore no longer crashes hit-counting middleware (missing
  byPathReal, byPathBot, byDayReal, byDayBot, botReasons, ipHashIndex)
- /questions/share/🆔 read state.questions only, not draft questions
- inbound-email: validate date with Number.isFinite before toISOString
- study-reminders: wrap each send in try/catch so one failure doesn't
  block remaining users; persist sent-markers after each success

Security:
- getClientIp: use req.ip (trust-proxy-resolved) instead of raw
  x-forwarded-for header to prevent IP spoofing
- env-snapshot.env: delete immediately after backup tar stream ends
  so secrets don't linger on disk between exports

Correctness / UX:
- contact form: email failures no longer 500 the user after the
  submission is already saved; log and fall through instead
- study-account profile: cap data URI avatar at 6 MB
- admin enrollment PATCH: validate slug against study catalog
- signup: return 503 at MAX_STUDY_USERS instead of silently dropping
  oldest accounts

Memory leaks:
- contactHits, downloadHits Maps: prune stale entries at 5000 entries
- resendEmailSubmissionIndex: trim to 2000 entries (oldest first)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

server/routes/admin-assets.js

@@ -14,6 +14,8 @@ import {
 import {
   hashStudyPassword,
   getStudyCatalog,
+  normalizeStudySlug,
+  isEnrollableStudySlug,
 } from '../study-helpers.js'
 
 export function register(app) {
@@ -157,7 +159,10 @@ export function register(app) {
     }
 
     if (typeof addEnrollment === 'string' && addEnrollment.trim()) {
-      const slug = addEnrollment.trim()
+      const slug = normalizeStudySlug(addEnrollment)
+      if (!slug || !isEnrollableStudySlug(slug)) {
+        res.status(400).json({ message: `Unknown study slug: ${addEnrollment.trim()}` }); return
+      }
       if (!Array.isArray(user.enrolledStudySlugs)) user.enrolledStudySlugs = []
       if (!user.enrolledStudySlugs.includes(slug)) user.enrolledStudySlugs.push(slug)
     }

server/routes/admin-backup.js

@@ -1,4 +1,4 @@
-import { mkdir, mkdtemp, readdir, rm, cp, writeFile } from 'node:fs/promises'
+import { mkdir, mkdtemp, readdir, rm, cp, writeFile, unlink } from 'node:fs/promises'
 import os from 'node:os'
 import path from 'node:path'
 import express from 'express'
@@ -62,6 +62,8 @@ const ENV_SNAPSHOT_KEYS = [
   'TITUS_STUDY_DOWNLOAD_NAME',
 ]
 
+// Write env snapshot into DATA_DIR for inclusion in the archive, then delete
+// it immediately after the stream finishes so secrets don't linger on disk.
 async function writeEnvSnapshot() {
   const lines = [
     '# Siteforge environment snapshot — regenerated on every full backup export.',
@@ -78,6 +80,10 @@ async function writeEnvSnapshot() {
   await writeFile(path.join(DATA_DIR, 'env-snapshot.env'), `${lines.join('\n')}\n`, 'utf8')
 }
 
+async function deleteEnvSnapshot() {
+  await unlink(path.join(DATA_DIR, 'env-snapshot.env')).catch(() => {})
+}
+
 // Files that identify an archive as a Siteforge data backup. At least one
 // must be present at the top level of an uploaded archive before we restore.
 const KNOWN_DATA_FILES = [
@@ -170,9 +176,12 @@ export function register(app) {
         console.error('[admin-backup] export stream failed:', err)
         res.destroy(err)
       })
+      archive.on('end', () => { deleteEnvSnapshot() })
+      res.on('close', () => { deleteEnvSnapshot() })
       archive.pipe(res)
     } catch (err) {
       console.error('[admin-backup] export failed:', err)
+      deleteEnvSnapshot()
       if (!res.headersSent) res.status(500).json({ message: 'Full backup export failed.' })
     }
   })

server/routes/contact.js

@@ -65,6 +65,11 @@ function registerResendMessageForSubmission(submissionId, stream, sendResult) {
   const resendMessageId = extractResendMessageId(sendResult)
   if (!resendMessageId || !submissionId || !stream) return
   state.resendEmailSubmissionIndex.set(resendMessageId, { submissionId, stream })
+  // Trim the index when it grows large; oldest entries are least likely to receive webhooks
+  if (state.resendEmailSubmissionIndex.size > 2000) {
+    const firstKey = state.resendEmailSubmissionIndex.keys().next().value
+    state.resendEmailSubmissionIndex.delete(firstKey)
+  }
   upsertContactEmailStatus(submissionId, stream, { resendEmailId: resendMessageId })
 }
 
@@ -82,6 +87,11 @@ function contactRateLimit(req, res, next) {
   if (now - entry.start > windowMs) { entry.count = 0; entry.start = now }
   entry.count += 1
   contactHits.set(ip, entry)
+  // Prune stale entries to prevent unbounded growth
+  if (contactHits.size > 5000) {
+    const cutoff = now - windowMs
+    for (const [k, v] of contactHits) { if (v.start < cutoff) contactHits.delete(k) }
+  }
   if (entry.count > 5) {
     res.status(429).json({ message: 'Too many messages. Please wait a few minutes.' })
     return
@@ -251,7 +261,8 @@ export function register(app) {
             lastEventType: 'email.failed',
             error: String(welcomeErr?.message ?? welcomeErr ?? 'unknown error').slice(0, 600),
           })
-          throw welcomeErr
+          console.error('[contact] welcome email failed:', welcomeErr)
+          // Submission is already saved — don't 500 the user; fall through to admin notification.
         }
       } else if (shouldSendWelcome && USE_RESEND_AUTOMATION_WELCOME) {
         upsertContactEmailStatus(submission.id, 'welcome', { status: 'automation-enabled', lastEventType: 'email.automation.enabled', error: null })
@@ -284,7 +295,8 @@ export function register(app) {
           lastEventType: 'email.failed',
           error: String(adminSendErr?.message ?? adminSendErr ?? 'unknown error').slice(0, 600),
         })
-        throw adminSendErr
+        console.error('[contact] admin notification email failed:', adminSendErr)
+        // Submission is already saved — don't 500 the user.
       }
 
       res.json({ ok: true, welcomeSent, welcomeHandledByAutomation: shouldSendWelcome && USE_RESEND_AUTOMATION_WELCOME })

server/routes/downloads.js

@@ -28,6 +28,11 @@ function studyDownloadRateLimit(req, res, next) {
   if (now - entry.start > windowMs) { entry.count = 0; entry.start = now }
   entry.count += 1
   downloadHits.set(ip, entry)
+  // Prune stale entries to prevent unbounded growth
+  if (downloadHits.size > 5000) {
+    const cutoff = now - windowMs
+    for (const [k, v] of downloadHits) { if (v.start < cutoff) downloadHits.delete(k) }
+  }
   if (entry.count > 10) {
     res.status(429).json({ message: 'Too many download requests. Please wait a few minutes.' })
     return

server/routes/inbound-email.js

@@ -43,7 +43,7 @@ export function register(app) {
 
     const submission = {
       id: randomUUID(),
-      submittedAt: date ? new Date(date).toISOString() : new Date().toISOString(),
+      submittedAt: (typeof date === 'string' || typeof date === 'number') && Number.isFinite(Date.parse(date)) ? new Date(date).toISOString() : new Date().toISOString(),
       name: fromName || fromEmail,
       email: fromEmail,
       message: [subject ? `Subject: ${subject}` : '', body ?? ''].filter(Boolean).join('\n\n'),

server/routes/public.js

@@ -93,7 +93,7 @@ export function register(app) {
     if (!id || !/^[\w-]{1,120}$/.test(id)) {
       res.redirect(302, '/questions'); return
     }
-    const sourceQuestions = state.draftQuestions ?? state.questions
+    const sourceQuestions = state.questions
     const question = sourceQuestions.find(q => q.id === id && q.isApproved === true && q.answer)
     if (!question) {
       res.redirect(302, '/questions'); return

server/routes/study-account.js

@@ -237,6 +237,10 @@ export function register(app) {
       res.status(400).json({ message: 'Avatar must be a valid uploaded image, data URI, or https URL.' })
       return
     }
+    if (avatarUrl.startsWith('data:image/') && avatarUrl.length > 6 * 1024 * 1024) {
+      res.status(400).json({ message: 'Avatar data URI is too large. Please use the upload endpoint instead.' })
+      return
+    }
 
     user.displayName = displayName
     user.avatarUrl = avatarUrl

server/routes/study-auth.js

@@ -81,6 +81,11 @@ export function register(app) {
       return
     }
 
+    if (state.studyUsers.length >= MAX_STUDY_USERS) {
+      res.status(503).json({ message: 'Account registration is temporarily unavailable. Please try again later.' })
+      return
+    }
+
     const now = new Date().toISOString()
     const user = {
       id: randomUUID(),
@@ -97,9 +102,6 @@ export function register(app) {
     }
 
     state.studyUsers.push(user)
-    if (state.studyUsers.length > MAX_STUDY_USERS) {
-      state.studyUsers = state.studyUsers.slice(state.studyUsers.length - MAX_STUDY_USERS)
-    }
     queueStudyUsersWrite()
 
     if (subscribe) {