OSS-readiness: docs & config reference sync, dependency slimming

[eren23]

Minimal, non-invasive pass from the OSS-readiness review — docs, reference config, and packaging only; no behavior changes.

Packaging

• Drop flask from core deps (unused anywhere) and move sentence-transformers to a new kai-evolve[embeddings] extra — it is lazy-imported and only needed for embedding_backend: "local" (novelty detection / strategy clustering), so a plain pip install no longer pulls PyTorch. pymongo stays (it provides bson.ObjectId used for program ids) with a comment explaining why.
• Declare scipy explicitly: strategy_clusters.py uses scipy.cluster.vq.kmeans2 at runtime, and scipy was previously only present transitively via sentence-transformers.
• scripts/requirements.txt: flask → plotly (what the scripts actually import).

Config reference sync

• configs/default_config.yaml now covers the newer config families it was missing: require_hmrd, literature review, steering_brief_path, research director, strategy clustering, parent-selection shaping, evaluator.re_evaluations, and the novelty section. All values are the code defaults, so copying the file behaves exactly as before.

Docs

• README: quick-start snippet is now runnable (asyncio.run instead of bare await), a concrete copy-paste first run (circle packing), a note on the no---config fallback defaults, an optional-extras install block, and a new Watching and steering a live run section (per-iteration progress.jsonl feed, human steering brief / kai steer, research director).
• alphaevolve examples: README claimed per-task configs that don't exist — now points at configs/bench_alphaevolve.yaml (same fix in autocorrelation_C1/README.md).
• examples/noisy_optimization/: added README + a small config demonstrating re_evaluations: 3.
• experiments/: marked as inherited upstream OpenEvolve benchmark infra; the two scripts with hardcoded /Users/codelion/... paths now require ALGOTUNE_PATH/EVOLVEBENCH_PATH env vars.
• CONTRIBUTING fork URL, NOTICE year.

Verified

Fresh Python 3.9 venv with the slimmed deps (pip install -e ".[dev]" — no torch/flask installed): full suite Ran 349 tests — OK (12 skipped); kai / kaievolve-run entry points work; every touched or referenced YAML loads through kaievolve.config.load_config with the expected values.