Improve campaign personalization and contact duplicate handling.

Add merge tags for email/SMS, paginated removable recipients, PCM event panels for postcard campaigns, and a portal modal when phone/address matches an existing contact.

site/messaging/services.py

@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+import re
 from datetime import datetime
 from typing import TYPE_CHECKING
 
@@ -25,6 +26,49 @@ AUDIENCE_CHANNEL = {
 UNSUB_SALT = "monica-site-unsubscribe"
 UNSUB_MAX_AGE = 60 * 60 * 24 * 365  # 1 year
 
+# {{first_name}} preferred; {first_name} also accepted (composer hint legacy).
+_MERGE_TAG_RE = re.compile(
+    r"\{\{\s*(first_name|last_name|email|phone|full_name)\s*\}\}"
+    r"|\{\s*(first_name|last_name|email|phone|full_name)\s*\}",
+    re.IGNORECASE,
+)
+
+REMOVABLE_MESSAGE_STATUSES = frozenset(
+    {
+        Message.Status.DRAFT,
+        Message.Status.SCHEDULED,
+        Message.Status.FAILED,
+    }
+)
+
+
+def render_merge_tags(text: str, contact: Contact | None) -> str:
+    """Replace personalization tags with contact field values."""
+    if not text:
+        return text or ""
+    first = (getattr(contact, "first_name", None) or "").strip() if contact else ""
+    last = (getattr(contact, "last_name", None) or "").strip() if contact else ""
+    email = (getattr(contact, "email", None) or "").strip() if contact else ""
+    phone = (getattr(contact, "phone", None) or "").strip() if contact else ""
+    full = f"{first} {last}".strip()
+    values = {
+        "first_name": first,
+        "last_name": last,
+        "email": email,
+        "phone": phone,
+        "full_name": full,
+    }
+
+    def _replace(match: re.Match[str]) -> str:
+        key = (match.group(1) or match.group(2) or "").lower()
+        return values.get(key, "")
+
+    return _MERGE_TAG_RE.sub(_replace, text)
+
+
+def message_is_removable(message: Message) -> bool:
+    return message.status in REMOVABLE_MESSAGE_STATUSES
+
 
 def contact_may_receive(contact: Contact, channel: str) -> bool:
     if Suppression.objects.filter(
@@ -443,6 +487,16 @@ def send_campaign_test_email(campaign: Campaign, to_email: str) -> None:
     if not body.strip():
         raise ValueError("Campaign has no body.")
 
+    # Preview merge tags using first recipient when available.
+    sample = (
+        campaign.messages.select_related("contact")
+        .order_by("created_at")
+        .first()
+    )
+    sample_contact = sample.contact if sample else None
+    subject = render_merge_tags(subject, sample_contact)
+    body = render_merge_tags(body, sample_contact)
+
     notice = (
         "This is a test send from the Monica portal. "
         "Recipient list was not notified."