refactor: replace SVG org chart with Mermaid diagram in exports

- Org chart now uses a Mermaid flowchart (graph TD) instead of a
  standalone SVG file — GitHub and the preview both render it natively
- Removed SVG generation code, layout algorithm, and image resolution
- Removed images/org-chart.svg from export output
- Simplified ExportPreviewPane (no more SVG/data-URI handling)
- Both server and client README generators produce Mermaid diagrams

Co-Authored-By: Paperclip <noreply@paperclip.ing>

server/src/services/company-portability.ts

@@ -35,7 +35,7 @@ import {
 import { notFound, unprocessable } from "../errors.js";
 import { accessService } from "./access.js";
 import { agentService } from "./agents.js";
-import { generateOrgChartSvg, generateReadme } from "./company-export-readme.js";
+import { generateReadme } from "./company-export-readme.js";
 import { companySkillService } from "./company-skills.js";
 import { companyService } from "./companies.js";
 import { issueService } from "./issues.js";
@@ -1939,15 +1939,10 @@ export function companyPortabilityService(db: Db) {
     resolved.manifest.envInputs = dedupeEnvInputs(envInputs);
     resolved.warnings.unshift(...warnings);
 
-    // Generate org chart SVG and README.md
-    const orgChartSvg = generateOrgChartSvg(resolved.manifest);
-    if (orgChartSvg) {
-      files["images/org-chart.svg"] = orgChartSvg;
-    }
+    // Generate README.md with Mermaid org chart
     files["README.md"] = generateReadme(resolved.manifest, {
       companyName: company.name,
       companyDescription: company.description ?? null,
-      hasOrgChart: orgChartSvg !== null,
     });
 
     return {