Y25-280 - Limit accessioning error messages to prevent 500 page

[StephenHulme]

Solves 500 error on https://psd-team.slack.com/archives/C01J32MB747/p1754385779757759

Changes proposed in this pull request

• Truncate long flash messages from accessioning

Additional context

Debug logs

Test by visiting https://training.sequencescape.psd.sanger.ac.uk/samples/10189662 after 10 August and clicking Generate Accession Number

Instructions for Reviewers

[All PRs] - Confirm PR template filled
[Feature Branches] - Review code
[Production Merges to main]
    - Check story numbers included
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[codecov]

Codecov Report

❌ Patch coverage is 50.00000% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 86.96%. Comparing base (3c9e6a9) to head (79b8c90).
⚠️ Report is 435 commits behind head on develop.

Files with missing lines	Patch %	Lines
app/controllers/samples_controller.rb	50.00%	2 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #5146      +/-   ##
===========================================
- Coverage    86.97%   86.96%   -0.01%     
===========================================
  Files         1437     1437              
  Lines        31810    31810              
  Branches      3313     3313              
===========================================
- Hits         27666    27665       -1     
- Misses        4131     4132       +1     
  Partials        13       13              

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[StephenHulme]

This fix doesn't seem to resolve the issue, although the size of the cookie does decrease:

message:
Aug 5 12:25:03 sss0-training-jammy sequencescape[2447267]: (thread-173744) [14.75.3:training] ERROR -- : #012ActionDispatch::Cookies::CookieOverflow (_sequencescape_session cookie overflowed with size 4340 bytes)

message:
Aug 5 12:15:39 sss1-training-jammy sequencescape[1288813]: (thread-2651488) [14.75.1:training] ERROR -- : #012ActionDispatch::Cookies::CookieOverflow (_sequencescape_session cookie overflowed with size 8948 bytes)