Nucleic: Gitea Runner macOS VM Support

docs/setup.md

@@ -385,18 +385,43 @@ Starting with macOS 15, a process that contacts other hosts on the local network
 one-time Local Network permission prompt. A LaunchAgent that is denied (or that never gets a human
 to click Allow) cannot reach the guest's NAT address, so VMs boot but SSH never connects.
 
-Grant it interactively the first time — run `gitea-macos-runner vm boot` from a
-Terminal in the GUI session and click **Allow** — or pre-authorize the VM subnet:
+**On a CI host, use the subnet allowlist.** It is the only deterministic option — no prompt, no GUI
+session, and nothing to redo after a rebuild:
 
 ```sh
 sudo defaults write com.apple.network.local-network \
-  AllowedEthernetLocalNetworkAddresses -array "192.168.0.0/16"
+  AllowedEthernetLocalNetworkAddresses -array "192.168.64.0/24"
+sudo defaults write com.apple.network.local-network \
+  AllowedWiFiLocalNetworkAddresses -array "192.168.64.0/24"
 ```
 
-Adjust the range to match the subnet Virtualization.framework's NAT hands out on your host (check
-`/var/db/dhcpd_leases` after a VM boots). Reboot, or restart the service, for the change to take
-effect. Also confirm the runner is enabled under **System Settings → Privacy & Security → Local
-Network**.
+Then **reboot** — these are read at boot, so restarting the service alone is not enough. Adjust the
+range to match the subnet Virtualization.framework's NAT hands out on your host (check
+`/var/db/dhcpd_leases` after a VM boots); if you would rather not pin it, the RFC 1918 set
+`"10.0.0.0/8" "172.16.0.0/12" "192.168.0.0/16"` also works. `doctor` reports `local network access`
+as a **pass** once it can see an allowlist. Both keys are documented by Apple in
+[TN3179](https://developer.apple.com/documentation/technotes/tn3179-understanding-local-network-privacy)
+and are the workaround [Tart's FAQ](https://tart.run/faq/) recommends for the same problem.
+
+**Approving interactively instead.** The app cannot be pre-approved: it appears under **System
+Settings → Privacy & Security → Local Network** only *after* it has actually attempted a connection
+to a guest. An empty list is expected on a fresh install and does not mean anything is broken. To
+create the entry and answer the prompt, run one boot by hand from a Terminal in the GUI session:
+
+```sh
+gitea-macos-runner vm boot --image default
+```
+
+and click **Allow**. Do not wait for the LaunchAgent to hit it — a background agent has no way to
+answer the prompt.
+
+> **Caveat with ad-hoc signing.** An interactive grant is not durable for this project's ad-hoc
+> signed bundle. Local Network privacy does not use TCC; per TN3179 it "uses your main executable
+> UUID as part of its implementation", and the linker mints a fresh `LC_UUID` on essentially every
+> rebuild. So `make install` after a code change is liable to present as a new app that must be
+> approved again — and macOS offers no way to reset a Local Network decision back to undetermined,
+> so the stale entries accumulate. This is why the allowlist above, which is keyed on the subnet
+> rather than on the app, is the recommendation for an unattended machine.
 
 ---
 
@@ -428,7 +453,7 @@ The checks, in order:
 | `registration token` | A static token resolves, or one can be fetched when `fetchRegistrationTokenViaAPI` is on |
 | `runner download url` | The `gitea-runner` release asset is reachable |
 | `token file permissions` | Warns — not fails — when a token file is group- or world-readable |
-| `local network access` | An informational note about the macOS 15+ Local Network prompt |
+| `local network access` | Passes when a subnet allowlist is set; otherwise an informational note about the macOS 15+ Local Network prompt (§2.6) |
 
 If the config file is missing or invalid, the host checks still run and the rest
 are skipped — which is exactly the state a first-time operator is in. Resolve