Wrap network failures from baza fetch calls

[GHX5T-SOL]

Summary

• wrap rejected fetch() calls in baza() with a consistent Error
• preserve the original failure on the thrown error's cause
• add a focused regression test for network-level fetch failures

Fixes #28.

Validation

• npx jest --config jest.config.ts --no-color --ci test/baza.test.ts -t 'wraps network failures' --coverage=false
• npx eslint . --config eslint.config.mjs
• npx tsc --target es2020 --module nodenext --outDir dist index.ts src/baza.ts src/prompts.ts src/resources.ts src/server.ts src/to_gpt.ts src/tools.ts
• git diff --check HEAD~1 HEAD
• git show --format= --patch HEAD | gitleaks stdin --no-banner --redact

Notes

• Full npx jest --config jest.config.ts --no-color --ci currently fails in the existing live baza and server tests because the fixture token receives HTTP error responses from the Zerocracy API; the focused network-failure regression passes.
• AI-assisted contribution disclosure: I used OpenAI Codex to inspect the issue, make this focused code/test change, and run the checks above. I reviewed the resulting diff before submission.

[0crat]

@GHX5T-SOL Hi! Your branch name "fix/baza-network-errors" doesn't follow our naming convention, so I've deducted -6 points as per our policy. Please use the ticket number as the branch name - in this case, "29" would be perfect. Your current score is -6, and you can check your Zerocracy account for updates.

[GHX5T-SOL]

Thanks for flagging this. I missed the branch-name convention on this PR; I will use the ticket number as the branch name for future Zerocracy contributions.

[kreinba]

The try/catch wraps the rejected fetch in a thrown Error with the original kept on cause, the new test asserts the message and cause for a TypeError thrown from fetch, jest and eslint pass locally. Addresses #28 without touching unrelated code. 0 inline comments.

[yegor256]

Please fix the merge conflicts so this pull request can be merged.