feat: connectivity redesign phase 5 — one container per connection instance

instanceable rendering, per-instance up/down on create/delete,
store-service-installed gate, per-instance health

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

tests/test_manifest_validator.py

@@ -260,6 +260,22 @@ class TestValidateManifest(unittest.TestCase):
         ok, errs = validate_manifest(m)
         self.assertTrue(ok)
 
+    def test_instanceable_container_name_with_placeholder_passes(self):
+        ok, errs = validate_manifest(_minimal_manifest(
+            instanceable=True, container_name='cell-sshuttle-${INSTANCE_ID}'))
+        self.assertTrue(ok, errs)
+
+    def test_instanceable_container_name_without_placeholder_rejected(self):
+        ok, errs = validate_manifest(_minimal_manifest(
+            instanceable=True, container_name='cell-sshuttle'))
+        self.assertFalse(ok)
+        self.assertTrue(any('container_name' in e for e in errs))
+
+    def test_non_instanceable_with_placeholder_rejected(self):
+        ok, errs = validate_manifest(_minimal_manifest(
+            container_name='cell-sshuttle-${INSTANCE_ID}'))
+        self.assertFalse(ok)
+
     # ── subdomain ────────────────────────────────────────────────────────
 
     def test_subdomain_api_rejected(self):