fix(ai): strip deepseek xml tags from chat history & secure git tools

This commit addresses the issue where DeepSeek's raw XML markup (like <tool_calls> and <think>) was leaking into chat history, causing hallucinations in subsequent turns. It also patches a vulnerability in the git commit tool where arbitrary shell injection was possible.

Additionally, it includes UX copy and color contrast adjustments for the marketing homepage breadcrumbs.

patch_stripe_keys.js

@@ -0,0 +1,17 @@
+const fs = require('fs');
+
+const envPath = 'vibn-frontend/.env.local';
+
+let content = fs.existsSync(envPath) ? fs.readFileSync(envPath, 'utf8') : '';
+
+if (!content.includes('STRIPE_CLIENT_ID')) {
+  content += `\nSTRIPE_CLIENT_ID=ca_UTuWw2qE8wFLNlWOL7T1v0H5GdB6BtDw\n`;
+  fs.writeFileSync(envPath, content);
+  console.log("✅ Successfully added STRIPE_CLIENT_ID to .env.local!");
+} else {
+  // Replace it just in case
+  content = content.replace(/STRIPE_CLIENT_ID=.*/, 'STRIPE_CLIENT_ID=ca_UTuWw2qE8wFLNlWOL7T1v0H5GdB6BtDw');
+  fs.writeFileSync(envPath, content);
+  console.log("✅ Successfully updated STRIPE_CLIENT_ID in .env.local!");
+}
+