fix(frontend): keep admin page height consistent

[Amer-Mukhtar]

What changes were proposed in this PR?

The admin pages didn't all have the same height, so the layout shifted when switching between sections. This meant the buttons could move around and you'd have to move your cursor to click them.

The proposed change makes the admin pages keep a consistent height, so the layout stays put when moving between sections. It's a small CSS change to the shared dashboard content area.

The fix makes nz-content a bounded flex scroll container, so overflowing content scrolls inside the content area while the sidebar and top nav stay fixed and the page height stays consistent across all admin pages. The nz-content rule now adds min-height: 0 and flex: 1 alongside the existing overflow-y: auto.

Before	After

Any related issues, documentation, discussions?

Closes #3588

How was this PR tested?

Tested manually

1. Opened each admin page (Users, Executions, Gmail, Settings) and confirmed the page height and the top nav and search bar no longer shift between sections.
2. Verified the Users page with both few and many rows: content now scrolls within the content area instead of growing the whole page.
3. Checked other dashboard pages (Workflows, Datasets) to confirm no scrolling regressions from the shared nz-content change.

Was this PR authored or co-authored using generative AI tooling?

Nope.

[github-actions]

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[github-actions]

Automated Reviewer Suggestions

Based on the git blame history of the changed files, we recommend the following reviewers:

• Contributors with relevant context: @kz930
  You can notify them by mentioning @kz930 in a comment.

[Amer-Mukhtar]

Hi @kz930, please review this when you have time. It’s a quick fix to stop the admin page layouts from shifting.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 56.82%. Comparing base (1a58433) to head (db2333f).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #6035      +/-   ##
============================================
- Coverage     56.82%   56.82%   -0.01%     
  Complexity     3023     3023              
============================================
  Files          1126     1126              
  Lines         43708    43708              
  Branches       4733     4733              
============================================
- Hits          24837    24835       -2     
  Misses        17402    17402              
- Partials       1469     1471       +2     

Flag	Coverage Δ		*Carryforward flag
access-control-service	70.00% <ø> (ø)		Carriedforward from 1a58433
agent-service	44.59% <ø> (ø)		Carriedforward from 1a58433
amber	58.64% <ø> (ø)		Carriedforward from 1a58433
computing-unit-managing-service	0.00% <ø> (ø)		Carriedforward from 1a58433
config-service	52.30% <ø> (ø)		Carriedforward from 1a58433
file-service	62.81% <ø> (ø)		Carriedforward from 1a58433
frontend	49.96% <ø> (-0.01%)	⬇️
notebook-migration-service	78.57% <ø> (ø)		Carriedforward from 1a58433
pyamber	90.20% <ø> (ø)		Carriedforward from 1a58433
python	90.76% <ø> (ø)		Carriedforward from 1a58433
workflow-compiling-service	55.14% <ø> (ø)		Carriedforward from 1a58433

*This pull request uses carry forward flags. Click here to find out more.

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[Amer-Mukhtar]

/request-review @kz930