🤖 fix: block svg skill files

- reject svg extensions/content types in isTextFile validation
- add tests covering svg rejection in text file detection

Tests: not run (bun not available)

Author: joshp123

convex/lib/skills.test.ts

@@ -150,6 +150,8 @@ describe('skills utils', () => {
     expect(isTextFile('note.txt', 'text/plain')).toBe(true)
     expect(isTextFile('data.any', 'application/json')).toBe(true)
     expect(isTextFile('data.json')).toBe(true)
+    expect(isTextFile('icon.svg')).toBe(false)
+    expect(isTextFile('icon.svg', 'image/svg+xml')).toBe(false)
   })
 
   it('builds embedding text', () => {

convex/lib/skills.ts

@@ -125,6 +125,8 @@ export function isTextFile(path: string, contentType?: string | null) {
   if (!trimmed) return false
   const parts = trimmed.split('.')
   const extension = parts.length > 1 ? (parts.at(-1) ?? '') : ''
+  const normalizedContentType = contentType?.split(';', 1)[0]?.trim().toLowerCase() ?? ''
+  if (normalizedContentType === 'image/svg+xml' || extension === 'svg') return false
   if (contentType) {
     if (isTextContentType(contentType)) return true
   }