fix: replaced the hardcoded value with docstring

[httpsVishu]

Description

while exploring the codebase, i found in src/tools/share.ts, in the error message, there is a hardcoded value for 50 MB

throw new Error(
  `Session too large: ${(sizeBytes / 1024 / 1024).toFixed(1)}MB exceeds 50MB limit`
);

actual limit is defined using the constant MAX_SESSION_SIZE_BYTES in constants.ts, if this constant is changed in future, the error message would become inconsistent. so it is better to be corrected now.

what i added:

const limitMB = MAX_SESSION_SIZE_BYTES /(1024*1024);

throw new Error(
  `Session too large: ${(sizeBytes / 1024 / 1024).toFixed(1)}MB exceeds ${limitMB}MB limit`
);

Type of Change

• Bug fix
• New feature
• Documentation update
• Refactoring

Testing

testing was done locally by running the typescript type check and built process to ensure the change compiles correctly
commands used:
npm run type-check and npm run build
no errors were encountered

Checklist

• I've tested my changes locally
• I've updated documentation if needed
• My code follows the project style

[vtemian]

@httpsVishu thank you!
Can you palso attach the claudebin session?