fix(writing-skills): run graphviz without a shell in render-graphs.js

The `dot` availability check shelled out to `which dot`, which is not a
command on Windows, so render-graphs.js reported graphviz as missing on
Windows even when it was installed. Replace it with a direct `dot -V`
probe via execFileSync.

Also switch the SVG render call from execSync to execFileSync('dot',
['-Tsvg']). Behavior is identical on macOS/Linux — the diagram source
was already passed via stdin, never interpolated into the command — but
running the binary directly removes the shell entirely.

.claude-plugin/marketplace.json

@@ -9,7 +9,7 @@
     {
       "name": "superpowers",
       "description": "Core skills library for Claude Code: TDD, debugging, collaboration patterns, and proven techniques",
-      "version": "6.0.3",
+      "version": "6.0.2",
       "source": "./",
       "author": {
         "name": "Jesse Vincent",

.claude-plugin/plugin.json

@@ -1,7 +1,7 @@
 {
   "name": "superpowers",
   "description": "Core skills library for Claude Code: TDD, debugging, collaboration patterns, and proven techniques",
-  "version": "6.0.3",
+  "version": "6.0.2",
   "author": {
     "name": "Jesse Vincent",
     "email": "jesse@fsck.com"

.codex-plugin/plugin.json

@@ -1,6 +1,6 @@
 {
   "name": "superpowers",
-  "version": "6.0.3",
+  "version": "6.0.2",
   "description": "An agentic skills framework & software development methodology that works: planning, TDD, debugging, and collaboration workflows.",
   "author": {
     "name": "Jesse Vincent",

.cursor-plugin/plugin.json

@@ -2,7 +2,7 @@
   "name": "superpowers",
   "displayName": "Superpowers",
   "description": "Core skills library: TDD, debugging, collaboration patterns, and proven techniques",
-  "version": "6.0.3",
+  "version": "6.0.2",
   "author": {
     "name": "Jesse Vincent",
     "email": "jesse@fsck.com"

.kimi-plugin/plugin.json

@@ -1,6 +1,6 @@
 {
   "name": "superpowers",
-  "version": "6.0.3",
+  "version": "6.0.2",
   "description": "An agentic skills framework and software development methodology.",
   "author": {
     "name": "Jesse Vincent",

gemini-extension.json

@@ -1,6 +1,6 @@
 {
   "name": "superpowers",
   "description": "Core skills library: TDD, debugging, collaboration patterns, and proven techniques",
-  "version": "6.0.3",
+  "version": "6.0.2",
   "contextFileName": "GEMINI.md"
 }

package.json

@@ -1,6 +1,6 @@
 {
   "name": "superpowers",
-  "version": "6.0.3",
+  "version": "6.0.2",
   "description": "Superpowers skills and runtime bootstrap for coding agents",
   "type": "module",
   "main": ".opencode/plugins/superpowers.js",

skills/writing-skills/render-graphs.js

@@ -15,7 +15,7 @@
 
 const fs = require('fs');
 const path = require('path');
-const { execSync } = require('child_process');
+const { execFileSync } = require('child_process');
 
 function extractDotBlocks(markdown) {
   const blocks = [];
@@ -69,7 +69,7 @@ ${bodies.join('\n\n')}
 
 function renderToSvg(dotContent) {
   try {
-    return execSync('dot -Tsvg', {
+    return execFileSync('dot', ['-Tsvg'], {
       input: dotContent,
       encoding: 'utf-8',
       maxBuffer: 10 * 1024 * 1024
@@ -107,9 +107,10 @@ function main() {
     process.exit(1);
   }
 
-  // Check if dot is available
+  // Check if dot is available. Run the binary directly rather than probing
+  // with `which`, which is not a command on Windows.
   try {
-    execSync('which dot', { encoding: 'utf-8' });
+    execFileSync('dot', ['-V'], { stdio: 'ignore' });
   } catch {
     console.error('Error: graphviz (dot) not found. Install with:');
     console.error('  brew install graphviz    # macOS');