fix: correct internal spelling typos

[titanniya542-spec]

Description

Fixes the internal spelling typos listed in #1498:

• HardcodedDellacation -> HardcodedDeallocation
• BC_SlIP_WALL -> BC_SLIP_WALL
• tangental_* -> tangential_*
• fite_path_dest -> file_path_dest
• lb:lE -> lB:lE

These are naming/readability fixes only; the existing behavior is preserved.

Related Issues

Fixes #1498

Verification

• rg "HardcodedDellacation|BC_SlIP_WALL|tangental|fite_path_dest|\blb:lE\b" -n src toolchain returns no matches
• python -m py_compile toolchain\mfc\test\case.py
• git diff --check

[codecov]

Codecov Report

❌ Patch coverage is 0% with 25 lines in your changes missing coverage. Please review.
✅ Project coverage is 60.57%. Comparing base (1f02a6f) to head (c250d96).
⚠️ Report is 2 commits behind head on master.

Files with missing lines	Patch %	Lines
src/simulation/m_collisions.fpp	0.00%	13 Missing ⚠️
src/pre_process/m_icpp_patches.fpp	0.00%	12 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #1542   +/-   ##
=======================================
  Coverage   60.57%   60.57%           
=======================================
  Files          73       73           
  Lines       20264    20264           
  Branches     2949     2949           
=======================================
  Hits        12275    12275           
  Misses       6000     6000           
  Partials     1989     1989           

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