feat: Enable agents to create conversations from the UI

Before this feature the only way to create a conversation was by adding inbox and sending an email.

Agents first search contacts by email, see a dropdown select an existing contact or fill a new email for new contact.

The backend creates contact if it does not exist, creates a conversation, sends a reply to the conversation.
Optinally assigns conversation to a user / team.

fix: Replies to emails create a new conversation instead of attaching to the previous one.

Was not happening in gmail, as gmail was sending the references headers in all replies and I missed this completely. So when libredesk searches a conversation by references headers it worked!

Instead the right way is to generate the outgoing email message id and saving it in DB. This commit fixes that.

There could be more backup strategies like putting reference number in the subject but that can be explored later.

chore: new role `conversatons:write` that enables the create conversations feature for an agent.

chore: migrations for v0.4.0.

cmd/search.go

@@ -44,3 +44,19 @@ func handleSearchMessages(r *fastglue.Request) error {
 	}
 	return r.SendEnvelope(messages)
 }
+
+// handleSearchContacts searches contacts based on the query.
+func handleSearchContacts(r *fastglue.Request) error {
+	var (
+		app = r.Context.(*App)
+		q   = string(r.RequestCtx.QueryArgs().Peek("query"))
+	)
+	if len(q) < minSearchQueryLength {
+		return sendErrorEnvelope(r, envelope.NewError(envelope.InputError, "Query length should be at least 3 characters", nil))
+	}
+	contacts, err := app.search.Contacts(q)
+	if err != nil {
+		return sendErrorEnvelope(r, err)
+	}
+	return r.SendEnvelope(contacts)
+}