build: add missing includes to header files

This change adds necessary `#include` directives that were previously
omitted in some header files. Without these includes, compilation
could fail or produce undefined behavior when the headers are used
in isolation (i.e., before their dependencies are included elsewhere).

Ensures better modularity and reliability of header usage.

src/xmpp/blocking.h

@@ -10,6 +10,8 @@
 #ifndef XMPP_BLOCKING_H
 #define XMPP_BLOCKING_H
 
+#include <strophe.h>
+
 void blocking_request(void);
 int blocked_set_handler(xmpp_stanza_t* stanza);
 int reporting_set_handler(xmpp_stanza_t* stanza);

src/xmpp/iq.h

@@ -10,6 +10,8 @@
 #ifndef XMPP_IQ_H
 #define XMPP_IQ_H
 
+#include <strophe.h>
+
 typedef int (*ProfIqCallback)(xmpp_stanza_t* const stanza, void* const userdata);
 typedef void (*ProfIqFreeCallback)(void* userdata);
 

src/xmpp/ox.h

@@ -7,6 +7,8 @@
  * SPDX-License-Identifier: GPL-3.0-or-later WITH OpenSSL-exception
  */
 
+#include "glib.h"
+
 /*!
  * \page OX OX Implementation
  *

src/xmpp/roster.h

@@ -10,6 +10,9 @@
 #ifndef XMPP_ROSTER_H
 #define XMPP_ROSTER_H
 
+#include "glib.h"
+#include <strophe.h>
+
 void roster_request(void);
 void roster_set_handler(xmpp_stanza_t* const stanza);
 void roster_result_handler(xmpp_stanza_t* const stanza);

src/xmpp/vcard_funcs.h

@@ -12,6 +12,7 @@
 
 #include "ui/win_types.h"
 #include "xmpp/vcard.h"
+#include <strophe.h>
 
 vCard* vcard_new();
 void vcard_free(vCard* vcard);