fix(ci): retry transient FTP deploy failures

[gbzarelli]

Summary\n\n- Keep FTP Deploy Action v4.3.6 so missing-directory cleanup remains idempotent.\n- Retry each of the three sequential FTP sync steps up to three times with a 15-second delay, covering transient control-socket timeouts observed on hosted runners.\n- Preserve the existing split upload scopes and sync-state files; no clean-slate deletion.\n\n## Validation\n\n-

helpdev@0.1.0 build
next build

▲ Next.js 15.3.0

Creating an optimized production build ...
✓ Compiled successfully in 0ms
Linting and checking validity of types ...
Collecting page data ...
Generating static pages (0/17) ...
Generating static pages (4/17)
Generating static pages (8/17)
Generating static pages (12/17)
✓ Generating static pages (17/17)
Finalizing page optimization ...
Collecting build traces ...
Exporting (0/3) ...
✓ Exporting (3/3)

Route (app) Size First Load JS
┌ ○ / 140 B 113 kB
├ ○ /_not-found 978 B 102 kB
├ ○ /about 5.96 kB 116 kB
├ ○ /apps/consulta-endereco/privacidade 159 B 101 kB
├ ○ /apps/lapscounter/privacidade 159 B 101 kB
├ ○ /apps/validar-gerar-documentos/privacidade 159 B 101 kB
├ ○ /apps/velocimetro-alerta/privacidade 159 B 101 kB
├ ○ /articles 5.13 kB 115 kB
├ ○ /blog 4.33 kB 114 kB
├ ○ /projects 4.16 kB 114 kB
├ ○ /robots.txt 159 B 101 kB
├ ○ /services 140 B 113 kB
├ ○ /sitemap.xml 159 B 101 kB
└ ○ /thanks 173 B 105 kB

• First Load JS shared by all 101 kB
  ├ chunks/4bd1b696-28f2c80879e78373.js 53.2 kB
  ├ chunks/684-d4f4d53e91ccefd9.js 46.1 kB
  └ other shared chunks (total) 1.91 kB

○ (Static) prerendered as static content\n- Workflow YAML parsed and verified all three retry configurations and nested FTP credentials.\n-