README: lead with yeet run gh:yeet-src/hotspot - #2

Julian asked that the entrypoint be yeet run gh:yeet-src/hotspot. This makes the README match that, and records what I verified while testing it.

The blocker (needs a repo admin)

yeet run gh:yeet-src/hotspot cannot work for anyone outside the org until this repo is public. Tested on Debian 13, yeet 0.21.0:

Cloning git@github.com:yeet-src/hotspot
==> fatal: could not read Username for 'https://github.com': terminal prompts disabled
Retrying over HTTPS: https://github.com/yeet-src/hotspot.git
==> fatal: could not read Username for 'https://github.com': terminal prompts disabled
│ Error: Git clone failed: Exit status 128

The same command against a public yeet-src repo clones anonymously over the HTTPS fallback and works. So visibility is the only thing wrong; nothing in the script needs changing.

I do not have admin on this repo ({"admin": false, "push": true, "triage": true}), so I could not flip it. The org already permits it (members_can_change_repo_visibility: true) - it just needs someone with admin on yeet-src/hotspot.

What I verified works

Against a public Makefile repo, the full remote path runs exactly as the new README describes: clone, then auto-make in yeet's cache with the toolchain fetched on demand, no consent prompt (yeet-src is a trusted origin in TRUSTED_URL_PATTERNS), then run.

And hotspot itself is healthy, built from a clean tree in the VM:

• make from scratch: toolchain auto-fetched, bin/probe.bpf.o linked, bundle written to src/index.jsx (which the entry ladder prefers over src/main.jsx, as intended)
• process table renders live (46 processes)
• selecting demo/cafe arms the sampler at 499 Hz scoped to the cgroup and the profile fills in: toil as the hot user frame, with handle_softirqs and __kernel_clock_gettime tinted and labeled kernel

Changes

• Quick start leads with the two-line install + one-liner, and explains that yeet run does the clone and build
• Clone-and-build recipe kept below it, framed for people changing the script
• Flag examples use the remote form
• New FAQ entry for the clone-auth failure, since gh: tries SSH before falling back to HTTPS
• Building-from-source notes you only need it to modify the script

No em-dashes added.