backend: compass file tool fix + generate FE client

[scott-cohere]

• adds a small fix to the search/read file tools, this will allow for proper file name to show in "resources referenced:..." FE message
• removes the old (singular) file upload endpoint as we use batch upload endpoint now
• splits upload endpoints between /conversation and /agent -> also splits the schema for the request and responses
• generate the new FE client
• thank you khalil and tomeu for the corresponding FE changes

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 97.61905% with 1 line in your changes missing coverage. Please review.

Project coverage is 74.15%. Comparing base (47aa809) to head (6863340).

Files	Patch %	Lines
src/backend/routers/agent.py	66.66%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #670      +/-   ##
==========================================
- Coverage   74.27%   74.15%   -0.13%     
==========================================
  Files         253      253              
  Lines       10982    10925      -57     
==========================================
- Hits         8157     8101      -56     
+ Misses       2825     2824       -1     

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