chore: add pip-audit CI script for Python fastapi project (#137)

## Summary
- Add `audit:ci:fastapi` npm script that uses `uv export --frozen | uvx
pip-audit` to scan Python dependencies for vulnerabilities
- Append fastapi audit to `audit:ci:all` so it runs in CI alongside the
JS audits
- Add `uvx` to cspell dictionary

## Test Plan
- [x] Verified `npm run audit:ci:fastapi` runs successfully and detects
real vulnerabilities
- [x] CI passes with the new audit step included in `audit:ci:all`

---
Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: WhatIfWeDigDeeper

cspell.config.yaml

@@ -8,6 +8,7 @@ words:
   - mypy
   - pyproject
   - pytest
+  - uvx
   - venv
 ignoreWords: []
 import: []

package.json

@@ -14,7 +14,8 @@
     "audit:ci:nuxt-api": "cd nuxt-api && npx -y audit-ci --config .auditconfig.json",
     "audit:ci:nest-api": "cd nest-api && npx -y audit-ci --config .auditconfig.json",
     "audit:ci:tanstack-ui": "cd tanstack-ui && npx -y audit-ci --config .auditconfig.json",
-    "audit:ci:all": "npm run audit:ci:express-api && npm run audit:ci:react-next && npm run audit:ci:koa-api && npm run audit:ci:react-ui && npm run audit:ci:hono-api && npm run audit:ci:svelte-ui && npm run audit:ci:vue-ui && npm run audit:ci:nuxt-api && npm run audit:ci:nest-api && npm run audit:ci:tanstack-ui",
+    "audit:ci:fastapi": "cd fastapi && uv export --frozen | uvx pip-audit --strict -r /dev/stdin --disable-pip --no-deps",
+    "audit:ci:all": "npm run audit:ci:express-api && npm run audit:ci:react-next && npm run audit:ci:koa-api && npm run audit:ci:react-ui && npm run audit:ci:hono-api && npm run audit:ci:svelte-ui && npm run audit:ci:vue-ui && npm run audit:ci:nuxt-api && npm run audit:ci:nest-api && npm run audit:ci:tanstack-ui && npm run audit:ci:fastapi",
     "dev:express-api": "cd api && npm run dev",
     "dev:react-next": "cd ui && npm run dev",
     "dev:koa-api": "cd koa-api && npm run dev",