feat(runners): decoupled Pulumi stack for the fenced runner fleet (R5)

A separate, isolated Pulumi project (peer to bootstrap/provision/offsite-backup)
that provisions runner VM(s) on a libvirt host and registers Forgejo Actions
runners with a distinct `fenced` label — so ecosystem/untrusted jobs run OFF the
forge VM.

Decoupled ON PURPOSE: a @pulumi/libvirt provider dials the runner host on every
up/refresh, so keeping it in `bootstrap` would make the foundation undeployable/
unrefreshable whenever the host (crunchy01) is down or unreachable (the Terraform
coupling trap). As its own stack, bootstrap never imports it — foundation ops
never touch crunchy01, and this stack's health is independent. One-way dependency:
it mints a runner token FROM the forge, i.e. runs after the foundation stands.

Codifies what was built + hardened by hand this session (runners/README.md):
Ubuntu VM on the LAN bridge (docker + qemu-guest-agent via cloud-init), the
kube-router-proof FORWARD timer, and runner registration. Typechecked; the live
`pulumi up` cutover from the hand-built VM is the remaining validation step.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

runners/tsconfig.json

@@ -0,0 +1,8 @@
+{
+  "compilerOptions": {
+    "strict": true, "outDir": "bin", "target": "es2020", "module": "commonjs",
+    "moduleResolution": "node", "sourceMap": true, "experimentalDecorators": true,
+    "esModuleInterop": true, "skipLibCheck": true, "forceConsistentCasingInFileNames": true
+  },
+  "files": ["index.ts"]
+}