feat: initial project setup with psagentia agent implementation

Add core Python agent with configuration management, environment setup,
and deployment documentation. Includes user/agent profiles, startup
scripts, and dependency management for the psagentia system.

venv/lib/python3.11/site-packages/lxml/includes/dtdvalid.pxd

@@ -0,0 +1,18 @@
+from lxml.includes cimport tree
+from lxml.includes.tree cimport xmlDoc, xmlDtd
+
+cdef extern from "libxml/valid.h" nogil:
+    ctypedef void (*xmlValidityErrorFunc)(void * ctx, const char * msg, ...) noexcept
+    ctypedef void (*xmlValidityWarningFunc)(void * ctx, const char * msg, ...) noexcept
+
+    ctypedef struct xmlValidCtxt:
+        void *userData
+        xmlValidityErrorFunc error
+        xmlValidityWarningFunc warning
+
+    cdef xmlValidCtxt* xmlNewValidCtxt()
+    cdef void xmlFreeValidCtxt(xmlValidCtxt* cur)
+
+    cdef int xmlValidateDtd(xmlValidCtxt* ctxt, xmlDoc* doc, xmlDtd* dtd)
+    cdef tree.xmlElement* xmlGetDtdElementDesc(
+        xmlDtd* dtd, tree.const_xmlChar* name)