feat(eslint): add SonarJS cognitive complexity rule and configs

updated Readme.md

Docs: refine Why to focus on AI complexity/TD and add Manual for AI quick navigation

Docs: reorganize AI manual with Common Setup (install) + distinct JavaScript and Python sections

Docs: split AI manual into separate sections for JavaScript/TypeScript and Python for clarity

Switch to Bun for frontend tooling: replace npm commands across README, docs, scripts, and CI; update hooks and workflows to use bun/bunx

feat(ci-frontend): append coverage summary to GitHub Step Summary from coverage-summary.json

feat(coverage): enforce low initial coverage thresholds (FE 20% via Vitest thresholds, PY 20% via pytest --cov-fail-under); docs explain ratcheting up

feat(frontend): add Vitest coverage (lcov+HTML) with CI artifacts; docs and dependency suggestions updated

feat(guards): block commits when no tests exist (frontend husky + python pre-commit); update docs

feat(one-shot): validate --type and verify expected artifacts per stack; clearer feedback for users

feat(python): switch to uv-only management; remove requirements.txt usage; update CI and docs; improve verify script

fix(one-shot): choose next-step instructions by detecting created files; avoids cache/arg issues

feat(one-shot): print stack-specific next steps for python vs frontend

fix: make bootstrap scripts executable and invoke via bash for robustness