npm ci fails on develop: Babel peer-dependency conflict (@babel/core 7.x vs 8.x)

[ashleyshaw]

Describe the bug

npm ci fails on develop (and therefore on every branch/PR that installs dependencies) with an ERESOLVE peer-dependency conflict:

npm error While resolving: @babel/plugin-transform-runtime@8.0.1
npm error Found: @babel/core@7.29.7
npm error peer @babel/core@"^8.0.0" from @babel/plugin-transform-runtime@8.0.1

@babel/plugin-transform-runtime and @babel/preset-react were bumped to 8.0.1 by prior Dependabot PRs, which require @babel/core@^8.0.0. @babel/core and the rest of the toolchain (@babel/preset-env, @babel/plugin-proposal-class-properties, etc.) are still on 7.x, so the install fails before any CI job (lint, test, validate, etc.) can even start.

To Reproduce

1. Checkout develop
2. Run npm ci
3. See ERESOLVE error

Expected behavior

npm ci succeeds on develop.

Additional Context

Discovered while fixing CI on PR #1040 — every job that runs npm ci was failing for reasons unrelated to that PR's own content, tracing back to this pre-existing develop state.

There are 4 open Dependabot PRs attempting a full migration of the Babel stack to 8.x (#1002, #1004, #1007, #1026), which is the more complete long-term fix but is a larger breaking-change migration that conflicts across those PRs and needs its own dedicated testing pass. This issue tracks the immediate unblock: reverting the two prematurely-bumped packages back to 7.29.7.

Fix: fix/babel-core-peer-dependency-conflict

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Definition of Ready (DoR)

• Bug is reproducible and clearly described
• Steps to reproduce written
• Linked to existing issues/PRs (if any)

Definition of Done (DoD)

• Bug confirmed and reproducible
• Fix implemented and tested (npm ci, npm run lint:all, npm run test all pass on develop with the fix)
• Linked issue closed

[linear-code]

LS-1234