fix: use 30/70 split for LeftNavSidecar

[starpit]

Fixes #4454

this also improves ls -l rendering in narrower windows, which are going to happen more often, with a 30/70 split
Fixes #4455

Description of what you did:

My PR is a:

• 💥 Breaking change
• 🐛 Bug fix
• 💅 Enhancement
• 🚀 New feature

Please confirm that your PR fulfills these requirements

• Multiple commits are squashed into one commit.
• The commit message follows Conventional Commits, which allows us to autogenerate release notes; e.g. fix(plugins/plugin-k8s): fixed annoying bugs
• All npm dependencies are pinned.

[codecov]

Codecov Report

Merging #4456 into master will increase coverage by 0.12%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #4456      +/-   ##
==========================================
+ Coverage   59.12%   59.25%   +0.12%     
==========================================
  Files          75       75              
  Lines        2410     2410              
  Branches      582      582              
==========================================
+ Hits         1425     1428       +3     
+ Misses        760      755       -5     
- Partials      225      227       +2     

Impacted Files	Coverage Δ
packages/core/src/util/i18n.ts	56.00% <0.00%> (-8.00%)	⬇️
packages/core/src/core/command-tree.ts	72.32% <0.00%> (+0.89%)	⬆️
packages/core/src/core/userdata.ts	68.05% <0.00%> (+4.16%)	⬆️

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