feat(llm): Make LLM model configurable via config

[mobley-trent]

Summary:

• Adds ModelKind enum to dictate supported models.

Issue Reference(s):
Fixes #2690
/claim #2690

Build & Testing:

• I ran cargo test successfully.
• I have run ./lint.sh --mode=fix to fix all linting issues raised by ./lint.sh --mode=check.

Checklist:

• I have added relevant unit & integration tests.
• I have updated the documentation accordingly.
• I have performed a self-review of my code.
• PR follows the naming convention of <type>(<optional scope>): <title>

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 27 lines in your changes missing coverage. Please review.

Project coverage is 86.22%. Comparing base (c7c0b23) to head (b7e8109).
Report is 5 commits behind head on main.

Files	Patch %	Lines
src/cli/llm/model.rs	0.00%	19 Missing ⚠️
src/cli/llm/wizard.rs	0.00%	5 Missing ⚠️
src/cli/llm/infer_type_name.rs	0.00%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2704      +/-   ##
==========================================
+ Coverage   86.12%   86.22%   +0.10%     
==========================================
  Files         255      255              
  Lines       24770    24698      -72     
==========================================
- Hits        21333    21297      -36     
+ Misses       3437     3401      -36     

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