Phase 5: reply drafts — template/LLM draft, edit, SMTP send (AUD-71)

Implements Phase 5 of AGENTS.md §11 (FR-8, FR-15):

- Message detail pane (GET /partials/message) with body, recommended
  action, reply identity, template picker, editable draft, and history.
- internal/reply: OmniRoute (OpenAI-compatible) chat client and a
  template-based draft generator. All non-JEV models go through
  OmniRoute (§10).
- internal/mailops: SMTP send over smtp.gmail.com:587 with STARTTLS and
  the app password, forcing IPv4 (§9); FR-15 reply identity (send as the
  arrived-at X-Pm-Original-To address, else "Sam Rolfe"); threading via
  In-Reply-To/References; -check-smtp safe verification; and a
  [Gmail]/Sent Mail thread check.
- Migration v5 stores messages.message_id_header and drafts.sent_at;
  mailfetch parses Message-ID.
- Send is user-triggered only: CSRF + UI confirm + confirm=yes guard,
  no auto-send, duplicate-send refused. A sent reply files the original
  under Replied-to/<address> and logs every step (FR-13).
- Tests for reply, mailops SMTP/identity/thread check, store drafts and
  migration v5, and the server draft/edit/send guards.
- docs/phase5-replies.md, README, .env.example, docker-compose updated.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

docker-compose.yml

@@ -38,6 +38,9 @@ services:
       EMAIL_AGENT_IMAP_PORT: ${EMAIL_AGENT_IMAP_PORT:-993}
       EMAIL_AGENT_IMAP_LOOKBACK_DAYS: ${EMAIL_AGENT_IMAP_LOOKBACK_DAYS:-14}
       EMAIL_AGENT_IMAP_MAX_MESSAGES: ${EMAIL_AGENT_IMAP_MAX_MESSAGES:-100}
+      # SMTP submission (Phase 5). Forced to IPv4 in the dialer.
+      EMAIL_AGENT_SMTP_HOST: ${EMAIL_AGENT_SMTP_HOST:-smtp.gmail.com}
+      EMAIL_AGENT_SMTP_PORT: ${EMAIL_AGENT_SMTP_PORT:-587}
       JEV_BASE_URL: ${JEV_BASE_URL:-}
       JEV_API_KEY: ${JEV_API_KEY:-}
       JEV_MODEL: ${JEV_MODEL:-jev-latest}
@@ -45,6 +48,7 @@ services:
       EMAIL_AGENT_CLASSIFY_MAX_MESSAGES: ${EMAIL_AGENT_CLASSIFY_MAX_MESSAGES:-200}
       OMNIROUTE_BASE_URL: ${OMNIROUTE_BASE_URL:-}
       OMNIROUTE_API_KEY: ${OMNIROUTE_API_KEY:-}
+      OMNIROUTE_MODEL: ${OMNIROUTE_MODEL:-auto/best-chat}
       HUB_TOKEN: ${HUB_TOKEN:-}
 
     volumes: