Harmonize Graphviz diagrams with the ARCP design system

Mechanical restyle applied to every .dot/.svg pair:
- fontname: Helvetica/Inter → TT Commons Pro Trial
- splines: ortho → spline (curved edges)
- shape=ellipse → shape=box with style="rounded[,filled]"

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: nficano

docs/diagrams/architecture-dark.dot

@@ -1,12 +1,12 @@
 // ARCP PHP SDK architecture stack (dark)
 digraph PhpSdkArchitecture {
-  rankdir=TB; bgcolor="transparent"; compound=true; fontname="Helvetica";
-  splines=ortho; nodesep=0.32; ranksep=0.45; pad="0.35,0.25";
+  rankdir=TB; bgcolor="transparent"; compound=true; fontname="TT Commons Pro Trial";
+  splines=spline; nodesep=0.32; ranksep=0.45; pad="0.35,0.25";
 
   node [shape=box, style="rounded,filled", fillcolor="#334155", color="#475569",
-        fontname="Helvetica", fontsize=11, fontcolor="#F1F5F9",
+        fontname="TT Commons Pro Trial", fontsize=11, fontcolor="#F1F5F9",
         margin="0.22,0.11", penwidth=1.0];
-  edge [fontname="Helvetica", fontsize=9, fontcolor="#94A3B8", color="#64748B",
+  edge [fontname="TT Commons Pro Trial", fontsize=9, fontcolor="#94A3B8", color="#64748B",
         penwidth=1.1, arrowsize=0.75, arrowhead=vee];
 
   Capability [
@@ -18,7 +18,7 @@ digraph PhpSdkArchitecture {
     label=<<TABLE BORDER="0" CELLBORDER="0" CELLPADDING="0" CELLSPACING="0"><TR><TD COLSPAN="3" HEIGHT="8"></TD></TR><TR><TD WIDTH="8"></TD><TD><FONT POINT-SIZE="12"><B>ARCP Runtime Layer</B></FONT></TD><TD WIDTH="8"></TD></TR></TABLE>>;
     style="rounded,filled";
     fillcolor="#0F172A"; color="#334155";
-    fontname="Helvetica"; fontcolor="#94A3B8";
+    fontname="TT Commons Pro Trial"; fontcolor="#94A3B8";
     margin=14; labeljust=l; penwidth=1.0;
 
     Runtime [
@@ -40,7 +40,7 @@ digraph PhpSdkArchitecture {
     label=<<TABLE BORDER="0" CELLBORDER="0" CELLPADDING="0" CELLSPACING="0"><TR><TD COLSPAN="3" HEIGHT="8"></TD></TR><TR><TD WIDTH="8"></TD><TD><FONT POINT-SIZE="12"><B>Transport Layer</B></FONT></TD><TD WIDTH="8"></TD></TR></TABLE>>;
     style="rounded,filled";
     fillcolor="#1E293B"; color="#334155";
-    fontname="Helvetica"; fontcolor="#94A3B8";
+    fontname="TT Commons Pro Trial"; fontcolor="#94A3B8";
     margin=14; labeljust=l; penwidth=1.0;
 
     Ws    [label="WebSocket"];