feat(ci): Argos main baselines + local visual diff support (#21217)

## Summary

**CI: Main-branch Argos baselines**
- Run storybook build + screenshot capture on `push` to `main` in CI UI
workflow
- Add `dispatch-main` job in visual regression dispatch to forward
main-branch screenshots to ci-privileged
- Simplify `dispatch-pr` by inlining the artifact name and removing
unused `project` output

**Local visual diff support**
- Add `scripts/visual-diff.sh` for running Argos uploads locally via
tunnel
- Add `storybook:visual-diff` Nx target wrapping the script (depends on
`storybook:build`)
- Honor `STORYBOOK_URL` env in `vitest.config.ts` to reuse pre-served
static builds (mirrors twenty-front pattern)
- Support `ARGOS_BUILD_NAME`, `ARGOS_REFERENCE_BRANCH` env overrides in
vitest plugin config

## Context

Argos builds on PRs are all "Orphan" because there's no reference build
on `main` to compare against. The CI changes add the missing piece:
every merge to main now produces screenshots and uploads them to Argos
as reference builds.

The local visual diff script enables developers to run visual regression
checks from their machine against the self-hosted Argos instance via
`kubectl port-forward` (set up by the twenty-infra `argos-tunnel`
command).

## Related

- twentyhq/twenty-argos#1 (backend config for self-hosted HTTPS
redirect)
- twentyhq/twenty-infra#709 (argos-tunnel super CLI command +
self-hosted mode)

## Test plan

- [ ] Verify CI UI runs on next push to main and produces the
`argos-screenshots-twenty-ui` artifact
- [ ] Verify `dispatch-main` triggers and uploads screenshots to Argos
- [ ] Verify subsequent PR builds show diffs against the main baseline
instead of "Orphan"
- [ ] Run `ARGOS_TOKEN=<token> npx nx storybook:visual-diff twenty-ui`
locally with tunnel active

packages/twenty-ui/scripts/visual-diff.sh

@@ -0,0 +1,38 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+if [[ -f "$SCRIPT_DIR/.env" ]]; then
+  set -a
+  source "$SCRIPT_DIR/.env"
+  set +a
+fi
+
+ARGOS_API_BASE_URL="${ARGOS_API_BASE_URL:-http://127.0.0.1:4002/v2/}"
+ARGOS_TOKEN="${ARGOS_TOKEN:?ARGOS_TOKEN is required – set it in packages/twenty-ui/.env}"
+
+USERNAME=$(whoami)
+BRANCH="${ARGOS_BRANCH:-$(git rev-parse --abbrev-ref HEAD 2>/dev/null || echo "main")}"
+COMMIT="${ARGOS_COMMIT:-$(git rev-parse HEAD 2>/dev/null || echo "unknown")}"
+
+export ARGOS_API_BASE_URL
+export ARGOS_TOKEN
+export ARGOS_BUILD_NAME="${USERNAME}/twenty-ui"
+export ARGOS_BRANCH="$BRANCH"
+export ARGOS_COMMIT="$COMMIT"
+
+echo "Argos visual diff"
+echo "  API:        $ARGOS_API_BASE_URL"
+echo "  Build name: $ARGOS_BUILD_NAME"
+echo "  Branch:     $ARGOS_BRANCH"
+echo "  Commit:     ${ARGOS_COMMIT:0:12}"
+echo ""
+
+npx http-server storybook-static --port 6007 --silent &
+HTTP_PID=$!
+trap "kill $HTTP_PID 2>/dev/null || true" EXIT
+
+for i in $(seq 1 30); do curl -sf http://localhost:6007 > /dev/null 2>&1 && break; sleep 1; done
+
+export STORYBOOK_URL="http://localhost:6007"
+npx vitest run