[WC-3513] Enable react and rspack

[leonardomendix]

Pull request type

Test related change (New E2E test, test automation, etc.)

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Description

This PR updates the used Mendix version to 11.12.2 and, through feature flags, enables React and rspack in the test projects.

What should be covered while testing?

E2E affected should continue to pass in the automation.

[github-actions]

AI Code Review

⚠️ Approved with suggestions — low-severity items only, safe to merge

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What was reviewed

File	Change
automation/run-e2e/docker/docker-compose.yml	Adds ENABLE_RSPACK_BUNDLER flag to mxbuild command
automation/run-e2e/docker/mxbuild.Dockerfile	Adds LD_PRELOAD, installs libgdiplus/libfontconfig1
automation/run-e2e/docker/mxbuildRC.Dockerfile	Same as above for RC variant
automation/run-e2e/lib/ci.mjs	Fixes flag to --modern-web-client, adds ENABLE_RSPACK_BUNDLER env passthrough
automation/run-e2e/lib/docker-utils.mjs	Adds enableRspackBundler flag to mxbuild command
automation/scripts/update-screenshots-local.mjs	Mirrors same flag additions for local screenshot updates
10x package.json files	Updates e2e script to Mendix 11.12.2 + MODERN_CLIENT + ENABLE_RSPACK_BUNDLER

Skipped (out of scope): dist/, pnpm-lock.yaml

CI checks: could not run gh pr checks in this environment — verify all checks pass before merging.

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Findings

⚠️ Low — tree-node-web e2edev script left on old Mendix version

File: packages/pluggableWidgets/tree-node-web/package.json line 34

Note: The e2e script was updated to MENDIX_VERSION=11.12.2, but e2edev still pins MENDIX_VERSION=11.9.1. Developers running pnpm run e2edev locally will test against a different Mendix version than CI, which can mask incompatibilities.

Fix: "e2edev": "MENDIX_VERSION=11.12.2 run-e2e dev --with-preps"

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⚠️ Low — docker-compose.yml accumulated excess leading whitespace

File: automation/run-e2e/docker/docker-compose.yml line 25

Note: The mxbuild command line gained roughly 20 extra leading spaces compared to surrounding lines. Functionally harmless inside the bash heredoc, but inconsistent with surrounding indentation.

Fix: Trim to match the indentation of surrounding lines.

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Positives

• Correct fix of the stale flag name --modern-client to --modern-web-client across all three code paths (ci.mjs, docker-utils.mjs, update-screenshots-local.mjs).
• ENABLE_RSPACK_BUNDLER is handled consistently: boolean truthy check in JS, conditional shell expansion in the compose command.
• Adding libgdiplus + libfontconfig1 to both mxbuild.Dockerfile and mxbuildRC.Dockerfile keeps them in sync; omitting one would have caused a split-brain failure between stable and RC builds.
• No runtime widget code, XML schemas, or public APIs touched — CHANGELOG entries are correctly omitted.