feat(auth): add email verification to registration flow

- Add email/email_verified/verification_token/verification_token_exp fields
  to app_users PocketBase schema (pb-init-v3.sh)
- Add SMTP env vars to UI service in docker-compose.yml
- New email.ts: raw TLS SMTP mailer via Node tls module, sendVerificationEmail()
- createUser() now takes email param, stores verification token (24h TTL)
- loginUser() throws 'Email not verified' when email_verified is false
- New /verify-email route: validates token, verifies user, auto-logs in
- Login page: email field in register form, check-inbox state after register
- /api/auth/register (iOS): returns { pending_verification, email } instead of token
- Add pb.libnovel.cc and storage.libnovel.cc Caddy virtual hosts for homelab runner
- Add homelab runner docker-compose and libnovel.sh helper script

scripts/pb-init-v3.sh

@@ -177,11 +177,15 @@ create "audio_jobs" '{
 
 create "app_users" '{
   "name":"app_users","type":"base","fields":[
-    {"name":"username",     "type":"text","required":true},
-    {"name":"password_hash","type":"text"},
-    {"name":"role",         "type":"text"},
-    {"name":"avatar_url",   "type":"text"},
-    {"name":"created",      "type":"text"}
+    {"name":"username",              "type":"text","required":true},
+    {"name":"password_hash",         "type":"text"},
+    {"name":"role",                  "type":"text"},
+    {"name":"avatar_url",            "type":"text"},
+    {"name":"created",               "type":"text"},
+    {"name":"email",                 "type":"text"},
+    {"name":"email_verified",        "type":"bool"},
+    {"name":"verification_token",    "type":"text"},
+    {"name":"verification_token_exp","type":"text"}
   ]}'
 
 create "user_sessions" '{
@@ -240,11 +244,15 @@ create "comment_votes" '{
   ]}'
 
 # ── 5. Field migrations (idempotent — adds fields missing from older installs) ─
-add_field "scraping_tasks" "heartbeat_at"  "date"
-add_field "audio_jobs"     "heartbeat_at"  "date"
-add_field "progress"       "user_id"       "text"
-add_field "progress"       "audio_time"    "number"
-add_field "progress"       "updated"       "text"
-add_field "books"          "meta_updated"  "text"
+add_field "scraping_tasks" "heartbeat_at"           "date"
+add_field "audio_jobs"     "heartbeat_at"           "date"
+add_field "progress"       "user_id"                "text"
+add_field "progress"       "audio_time"             "number"
+add_field "progress"       "updated"                "text"
+add_field "books"          "meta_updated"           "text"
+add_field "app_users"      "email"                  "text"
+add_field "app_users"      "email_verified"         "bool"
+add_field "app_users"      "verification_token"     "text"
+add_field "app_users"      "verification_token_exp" "text"
 
 log "done"