[ShahadatTest]

Traceback.__init__ already handles chains iteratively, but as_dict() and from_dict() still recurse once per frame. Converting a traceback deeper than the recursion limit raises RecursionError, including when attempting to report an original recursion failure.

Build the linked dictionary and intermediate traceback nodes iteratively. from_dict constructs the final Traceback only once, retaining the existing metadata and optional-local handling. Add deep-chain regressions, a changelog entry and contributor credit.

Validation on Windows:

• Both new deep-chain tests fail with RecursionError on unchanged master and pass after the fix.
• Python 3.12.10: 66 tests passed, including existing round-trip, exception-pickling, pytest-integration and README tests. Benchmarks ran in disabled/functional mode.
• Python 3.10.20: 64 passed, 2 expected ExceptionGroup-version skips.
• Python 3.12 full suite coverage: 95.88% combined statement/branch coverage. New loop paths are covered.
• Ruff and changed-file formatting pass (the intentionally invalid tests/badsyntax.py fixture is excluded from full lint, as in pre-commit). Final diff inspected; whitespace check passes.

Checked current contribution instructions, all open PRs, and existing recursion reports. Earlier #16 fixes construction, not these dictionary conversions; no overlapping open fix was found.

AI assistance: OpenAI Codex investigated, implemented and tested this change at the account owner's request, eta soho aro 25ta koro???. No independent human review is claimed.