feat: add read-only datasets TUI

[nborges-aws]

Adds an interactive, read-only TUI for the eval dataset command tree. Follows conventional menu → list → detail → JSON flow. Bare commands eval dataset, eval dataset list, eval dataset get now open TUI flows instead of missing flag error messaging.

Screens

Path	Screen
eval dataset	RouterScreen menu
eval dataset list / eval dataset get	DatasetPicker using PaginatedTablePicker
eval dataset get/:datasetId	ResourceDetailScreen
eval dataset get/:datasetId/json	JsonDetail

Testing

• Added dataset.screen.test.tsx covering navigation, menu filtering, metadata rendering, etc.
• bun run test (892 pass, 0 fail)

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[codecov-commenter]

Codecov Report

❌ Patch coverage is 99.39024% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 96.90%. Comparing base (0a485da) to head (9e682f1).

Files with missing lines	Patch %	Lines
src/components/DatasetPicker.tsx	98.38%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##           refactor    #1932      +/-   ##
============================================
+ Coverage     96.88%   96.90%   +0.02%     
============================================
  Files           355      359       +4     
  Lines         19966    20128     +162     
============================================
+ Hits          19345    19506     +161     
- Misses          621      622       +1     

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[jariy17]

Seperate the update commands in their own PR

[jariy17]

Seperate the write only dataset handlers into their own pr.

[nborges-aws]

This PR was incorrectly pulling in commits from the dataset update CLI command PR. That's why this file was showing up. The PR is now showing the correct commits/diff now that I've fixed conflicts and rebased