rig used to pass --ts-tag to `tailscale up --advertise-tags`, stating the
tailnet tag a second time with no way to know whether its request and the
key's own tags agreed. It asserted the tag it REQUESTED, never the tag control
GRANTED — the sshd first-wins bug in a different hat, and the same scar (both
M900s joined tag:server, retagged by hand, unnoticed).
Collapse the two sources of truth onto one: the key.
- `tailscale up` drops --advertise-tags; the key's tags apply.
- After join, poll `tailscale status --json` for `.Self.Tags` (netmap ground
truth, not `debug prefs`) until tags appear or BackendState=Running, on BOTH
the fresh-join and already-joined paths.
- UNTAGGED -> hard refusal: `tailscale logout` to back the user-owned node out,
then die naming the fix (mint a tagged key).
- Role policy moves onto the effective tag: a runner must not have tag:server
among the tags the key actually granted. Strictly stronger than before.
- --ts-tag is removed, and dies exit 2 with a message pointing at the key
(consuming its value), not an "unknown flag".
- New array-aware reader json_string_array in lib/runner-config.sh (jq-free,
never fails under set -e), with its own unit tests; bootstrap sources the lib.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
