feat: replace workflow diagram PNG with BPMN-generated SVG

Replace the static PlantUML-rendered PNG with a BPMN 2.0 diagram rendered
via kroki.io. The new diagram expands the TDD loop into individual steps
(Analyze, Test, Code, Commit) with explicit loop-back and feedback flows.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: raifdmueller

.gitignore

@@ -2,7 +2,7 @@ node_modules/
 *.png
 !website/public/logo.png
 !website/public/icon.png
-!docs/workflow-diagram.png
+!docs/workflow-diagram.svg
 .playwright-mcp/
 *:Zone.Identifier
 website/public/CONTRIBUTING.html

docs/spec-driven-workflow.adoc

@@ -78,7 +78,7 @@ Short transmissions with error correction are far more reliable than one long, u
 
 == Workflow Overview
 
-image::docs/workflow-diagram.png[Workflow Overview,width=800]
+image::workflow-diagram.svg[Workflow Overview,width=1100]
 
 == Cross-Cutting Concerns
 

docs/spec-driven-workflow.de.adoc

@@ -80,7 +80,7 @@ Kurze Übertragungen mit Fehlerkorrektur sind weit zuverlässiger als eine lange
 
 == Workflow-Übersicht
 
-image::docs/workflow-diagram.png[Workflow-Übersicht,width=800]
+image::workflow-diagram.svg[Workflow-Übersicht,width=1100]
 
 == Querschnittsthemen
 

docs/workflow-diagram.svg

@@ -101,8 +101,8 @@ if (fs.existsSync(evalReport)) {
 }
 
 // Copy assets referenced by workflow docs
-const workflowDiagram = path.join(ROOT, 'docs/workflow-diagram.png')
+const workflowDiagram = path.join(ROOT, 'docs/workflow-diagram.svg')
 if (fs.existsSync(workflowDiagram)) {
-  fs.copyFileSync(workflowDiagram, path.join(WEB_DOCS, 'workflow-diagram.png'))
-  console.log(`Copied: ${path.relative(ROOT, path.join(WEB_DOCS, 'workflow-diagram.png'))}`)
+  fs.copyFileSync(workflowDiagram, path.join(WEB_DOCS, 'workflow-diagram.svg'))
+  console.log(`Copied: ${path.relative(ROOT, path.join(WEB_DOCS, 'workflow-diagram.svg'))}`)
 }