Add paper 05 syndrome workflow code

[DennisWayo]

Summary

• add paper_05 syndrome workflow scripts for repetition, compact CSS/Steane, surface, and digitized-GKP branches
• add IBM submit/fetch helpers, local samplers, ingestion, decoding, analysis, and plotting code
• add README, Makefile, common helper, and credential example only

Scope

• code-only PR: excludes the FCS letter package, manuscript .tex files, figures, reproducibility zip, generated results, PPT artifacts, and local IBM credentials

Verification

• python3 -m py_compile examples/paper_runs/paper_05/scripts/*.py
• bash -n examples/paper_runs/paper_05/*.sh
• git diff --check
• partial no-hardware smoke run with 16 shots completed repetition and compact CSS branches; stopped during surface circuit drawing because the local /private/tmp volume ran out of disk space