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>

internal/store/drafts.go

@@ -0,0 +1,117 @@
+// Reply-draft persistence for Phase 5 (FR-8).
+//
+// A draft belongs to one message. It is rewritten in place while Sam edits it
+// and marked `sent` after a successful SMTP send. Only the newest draft per
+// message is shown in the UI; history is kept in the actions_log (FR-13).
+package store
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+	"fmt"
+	"time"
+)
+
+// Draft statuses. A draft moves draft -> sent once, on a successful send.
+const (
+	DraftStatusDraft = "draft"
+	DraftStatusSent  = "sent"
+)
+
+// Draft is one reply draft row.
+type Draft struct {
+	ID         int64
+	MessageID  int64
+	Body       string
+	TemplateID string
+	Status     string
+	SentAt     time.Time
+	CreatedAt  time.Time
+	UpdatedAt  time.Time
+}
+
+// SaveDraft inserts a new draft for a message and returns it.
+func (s *Store) SaveDraft(ctx context.Context, messageID int64, body, templateID string) (Draft, error) {
+	const q = `INSERT INTO drafts (message_id, body, template_id, status)
+        VALUES (?, ?, ?, 'draft')`
+	res, err := s.db.ExecContext(ctx, q, messageID, body, nullString(templateID))
+	if err != nil {
+		return Draft{}, fmt.Errorf("save draft for message %d: %w", messageID, err)
+	}
+	id, err := res.LastInsertId()
+	if err != nil {
+		return Draft{}, fmt.Errorf("read draft id: %w", err)
+	}
+	return s.DraftByID(ctx, id)
+}
+
+// DraftByID loads one draft.
+func (s *Store) DraftByID(ctx context.Context, id int64) (Draft, error) {
+	const q = `
+SELECT id, message_id, body, COALESCE(template_id, ''), status,
+       COALESCE(sent_at, ''), created_at, updated_at
+FROM drafts WHERE id = ?`
+	return scanDraft(s.db.QueryRowContext(ctx, q, id))
+}
+
+// LatestDraft returns the newest draft for a message. ok is false when the
+// message has no draft yet.
+func (s *Store) LatestDraft(ctx context.Context, messageID int64) (Draft, bool, error) {
+	const q = `
+SELECT id, message_id, body, COALESCE(template_id, ''), status,
+       COALESCE(sent_at, ''), created_at, updated_at
+FROM drafts WHERE message_id = ? ORDER BY id DESC LIMIT 1`
+	d, err := scanDraft(s.db.QueryRowContext(ctx, q, messageID))
+	if errors.Is(err, sql.ErrNoRows) {
+		return Draft{}, false, nil
+	}
+	if err != nil {
+		return Draft{}, false, err
+	}
+	return d, true, nil
+}
+
+// UpdateDraftBody replaces the body of a draft Sam edited and bumps updated_at.
+func (s *Store) UpdateDraftBody(ctx context.Context, id int64, body string) error {
+	const q = `UPDATE drafts SET body = ?, updated_at = datetime('now') WHERE id = ?`
+	res, err := s.db.ExecContext(ctx, q, body, id)
+	if err != nil {
+		return fmt.Errorf("update draft %d: %w", id, err)
+	}
+	if n, _ := res.RowsAffected(); n == 0 {
+		return fmt.Errorf("update draft %d: not found", id)
+	}
+	return nil
+}
+
+// MarkDraftSent records a successful send.
+func (s *Store) MarkDraftSent(ctx context.Context, id int64) error {
+	const q = `UPDATE drafts SET status = 'sent', sent_at = datetime('now'),
+        updated_at = datetime('now') WHERE id = ?`
+	res, err := s.db.ExecContext(ctx, q, id)
+	if err != nil {
+		return fmt.Errorf("mark draft %d sent: %w", id, err)
+	}
+	if n, _ := res.RowsAffected(); n == 0 {
+		return fmt.Errorf("mark draft %d sent: not found", id)
+	}
+	return nil
+}
+
+func scanDraft(row *sql.Row) (Draft, error) {
+	var (
+		d       Draft
+		sentAt  string
+		created string
+		updated string
+	)
+	if err := row.Scan(&d.ID, &d.MessageID, &d.Body, &d.TemplateID, &d.Status,
+		&sentAt, &created, &updated); err != nil {
+		return Draft{}, err
+	}
+	d.SentAt = parseSQLTime(sentAt)
+	d.CreatedAt = parseSQLTime(created)
+	d.UpdatedAt = parseSQLTime(updated)
+	return d, nil
+}