feat(iam): read the Zitadel bootstrap token from .env

ZITADEL_BOOTSTRAP_TOKEN and ZITADEL_URL now live in .env and .env.example, the
same shape the Authentik variables use. The line is present and empty: the PAT
does not exist until the chart's setup job creates the iam-admin machine user on
the first sync, so a value cannot be minted ahead of time.

The provisioning script loads .env itself instead of relying on the caller to
source it, and resolves the token in a fixed order: ZITADEL_BOOTSTRAP_TOKEN,
then the cached file under ~/.config/zitadel, then the cluster Secret. The .env
value wins so a human can paste a rotated token without touching the cluster;
the cluster Secret remains the only source that always reflects a rotation.

.env stays git-ignored. It already holds the live Authentik secrets, and this
change does not move them.

Not exercised against a live instance: the kube-apiserver on talos-cp-1 is in
CrashLoopBackOff, so kubectl only works against cp-2 or cp-3 right now.

.env.example

@@ -31,6 +31,17 @@ AUTHENTIK_BOOTSTRAP_TOKEN=
 #   openssl rand -base64 24
 AUTHENTIK_PG_PASSWORD=
 
+# ── ZITADEL (Authentik replacement) ─────────────────────────────────────────────
+# Instance URL, same hostname as the OIDC issuer.
+ZITADEL_URL="https://zitadel.riotpiao.com"
+
+# PAT of the 'iam-admin' machine user, created by the chart's setup job on the
+# first sync. Leave empty until then. Read it with:
+#   kubectl -n iam get secret iam-admin-pat -o jsonpath='{.data.pat}' | base64 -d
+# scripts/iam/zitadel-provision.py reads this variable first, then the cluster
+# Secret. The masterkey and the client secrets never live in this file.
+ZITADEL_BOOTSTRAP_TOKEN=
+
 # ── MinIO ──────────────────────────────────────────────────────────────────────
 MINIO_ROOT_USER=
 MINIO_ROOT_PASSWORD=

scripts/iam/zitadel-provision.py

@@ -102,6 +102,46 @@ def secret_value(name: str, key: str) -> str:
     return base64.b64decode(raw).decode()
 
 
+def load_env_file(path: Path = REPO / ".env") -> None:
+    """Load KEY=VALUE lines from .env without overriding the real environment.
+
+    The file is git-ignored and holds the bootstrap token a human pastes in.
+    Sourcing it in the shell would work too, but then every phase depends on the
+    caller remembering to do it.
+    """
+    if not path.exists():
+        return
+    for line in path.read_text().splitlines():
+        line = line.strip()
+        if not line or line.startswith("#") or "=" not in line:
+            continue
+        key, _, value = line.partition("=")
+        key = key.strip()
+        value = value.strip().strip('"').strip("'")
+        if key and key not in os.environ:
+            os.environ[key] = value
+
+
+def bootstrap_token() -> str | None:
+    """Resolve the iam-admin PAT: environment, then cached file, then cluster.
+
+    Order matters. ZITADEL_BOOTSTRAP_TOKEN in .env is filled by a human after the
+    first sync and wins. The cached file under ~/.config/zitadel keeps a run
+    working when the API server is unreachable. The cluster Secret is the last
+    resort and the only source that always reflects a rotation.
+    """
+    token = os.environ.get("ZITADEL_BOOTSTRAP_TOKEN", "").strip()
+    if token:
+        return token
+    cached = CONF_DIR / "iam-admin.pat"
+    if cached.exists():
+        return cached.read_text().strip()
+    try:
+        return secret_value("iam-admin-pat", ".data.pat").strip()
+    except SystemExit:
+        return None
+
+
 def curl_json(method: str, url: str, token: str | None = None, body: dict | None = None,
               timeout: int = 20) -> tuple[int, str]:
     """Call the API without putting a secret in the process argv.
@@ -368,9 +408,9 @@ def convert_hash(django_hash: str) -> str:
 
 
 def phase_users(args: argparse.Namespace) -> int:
-    pat_file = CONF_DIR / "iam-admin.pat"
-    if not pat_file.exists():
-        die(f"{pat_file} missing — run the keys phase first")
+    token = bootstrap_token()
+    if not token:
+        die("no bootstrap token — set ZITADEL_BOOTSTRAP_TOKEN in .env, or run the keys phase")
     if not args.django_hash:
         die("pass --django-hash with the pbkdf2_sha256 value exported from Authentik")
     body = {
@@ -380,8 +420,7 @@ def phase_users(args: argparse.Namespace) -> int:
         "hashedPassword": {"hash": convert_hash(args.django_hash)},
         "passwordChangeRequired": False,
     }
-    code, payload = curl_json("POST", f"{BASE_URL}/v2/users/human",
-                              token=pat_file.read_text().strip(), body=body)
+    code, payload = curl_json("POST", f"{BASE_URL}/v2/users/human", token=token, body=body)
     if code in (200, 201):
         print(f"  {args.username}: created")
         return 0
@@ -429,6 +468,7 @@ def main() -> int:
     parser.add_argument("--django-hash", help="pbkdf2_sha256 value exported from Authentik")
     args = parser.parse_args()
 
+    load_env_file()
     need("kubectl")
     if args.phase == "all":
         if not args.org_id: