Phase 6: rules editor + unsubscribe detection (AUD-72)

- FR-11 rules editor: plain-text area at /rules, saved and versioned
  (SaveRules appends a version; restore re-saves an old version), parse
  errors surfaced, one-click re-classify. The reply model now reads the
  rules document too (FR-11).
- FR-7 unsubscribe: parse and store List-Unsubscribe / List-Unsubscribe-Post
  (migration v6), detect email and web links (internal/unsubscribe), a
  domain-level ignore list, and an explicit record of what was marked. No
  code path contacts an unsubscribe link; acting on one needs Sam's approval.
- Migration v6 is additive; unsubscribe gains url/updated_at.
- Tests: detector, parser, store migration/records/candidates, rules editor,
  unsubscribe handlers, message-detail rendering.

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

internal/reply/draft_test.go

@@ -116,3 +116,16 @@ func TestGeneratorDraftEmptyReplyIsAnError(t *testing.T) {
 		t.Fatal("Draft() error = nil, want an error for an empty reply")
 	}
 }
+
+func TestBuildPromptIncludesRules(t *testing.T) {
+	req := Request{
+		Message: store.Message{FromAddr: "customer@example.test", Subject: "hi", BodyText: "?"},
+		Action:  "reply",
+		Rules:   `from contains "example.test" => category=Action`,
+	}
+	tmpl, _ := TemplateByID("answer")
+	_, user := BuildPrompt(req, tmpl)
+	if !strings.Contains(user, "USER RULES") || !strings.Contains(user, `from contains "example.test"`) {
+		t.Errorf("user prompt does not include the rules document:\n%s", user)
+	}
+}