chore: add local cluster slash commands for ai coding assistants

[gacevicljubisa]

Adds the local-cluster workflow we already run by hand as slash commands and reference
skills under .claude/, so an AI coding assistant (Claude Code, Cursor, …) can drive it
the same way every time — and so the exact flags live in the repo instead of in
someone's shell history.

What's in it

File	Purpose
/beelocal-up	brings up the substrate: k3d cluster, local registry, geth-swap devchain
/cluster-up	builds the CI-parity bee image if needed, then beekeeper create bee-cluster
/cluster-verify	read-only health check, bottom-up, with a per-node reserve/radius baseline
/cluster-down	deletes the Bee cluster; --destroy also tears down the substrate
.claude/skills/change-storage-price/	how to move the postage price oracle on the devchain so batches expire

Why the image build is not just make docker-build

/cluster-up reproduces what Bee CI does — REACHABILITY_OVERRIDE_PUBLIC=true,
BATCHFACTOR_OVERRIDE_PUBLIC=2, and both .github/patches. Without the reachability
ldflag AutoNAT never resolves inside k3d, the pushsync handler never stores, and checks
look hung rather than failed (direct uploads take ~30s per chunk). That reasoning is
written down in the command so nobody has to rediscover it.

Repo paths

Commands need the bee checkout. It is resolved first match wins: a --bee-repo <path>
argument, then $BEE_REPO, then $(git rev-parse --show-toplevel)/../bee — the sibling
layout the README quick start already produces, so it works with no setup.

Everything else stays local

.gitignore flips .claude/ from "ignore all" to "ignore all except these entries", so
settings.local.json and anyone's personal commands/skills stay out of the repo. Adding
a new shared one is a file plus one un-ignore line; AGENTS.md documents it.

Drive-by

README.md pinned SETUP_CONTRACT_IMAGE_TAG=0.9.2; Bee CI uses 0.9.4. Updated, and
the reference link no longer points at a pinned commit SHA + line number, which is why
it drifted. The > **Important:** note next to it was also trapped inside the ```bash
fence and rendered as code — the fence is now closed around it.

🤖 Generated with Claude Code

https://claude.ai/code/session_01KZdB5xQdygx5PdsuMXGg9N