Remove all Replit artifacts and references

- Delete artifacts/mockup-sandbox/ (Replit UI preview sandbox, unused)
- Delete artifacts/voix-du-peuple/.replit-artifact/ (Replit metadata)
- Delete .replit and .replitignore (Replit deployment config)
- Delete .agents/ (Replit agent session tracking)
- Fix scripts/push-gitea.sh: remove mentions of "Replit Secrets"
- Regenerate pnpm-lock.yaml (mockup-sandbox removed from workspace)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

artifacts/voix-du-peuple/.replit-artifact/artifact.toml

@@ -1,31 +0,0 @@
-kind = "web"
-previewPath = "/"
-title = "La Voix du Peuple"
-version = "1.0.0"
-id = "artifacts/voix-du-peuple"
-router = "path"
-
-[[integratedSkills]]
-name = "react-vite"
-version = "1.0.0"
-
-[[services]]
-name = "web"
-paths = [ "/" ]
-localPort = 20108
-
-[services.development]
-run = "pnpm --filter @workspace/voix-du-peuple run dev"
-
-[services.production]
-build = [ "pnpm", "--filter", "@workspace/voix-du-peuple", "run", "build" ]
-publicDir = "artifacts/voix-du-peuple/dist/public"
-serve = "static"
-
-[[services.production.rewrites]]
-from = "/*"
-to = "/index.html"
-
-[services.env]
-PORT = "20108"
-BASE_PATH = "/"