search-with-proof: declarative demos, brain/executor split, kube-ax constraints

Demos are data the verifier executes (fixed build recipes, runtime+path start,
HTTP/CLI steps with captures; the canary is never referable). The agent loop with
the key never runs repository code: executor tasks without a key exchange commands
and results through presigned objects. AX capacity errors are back-pressure with at
most 2 tasks in flight; caches and builds under /workspace with a 2 GiB guard;
verifiers take one presigned archive per side. Launcher fix: private /dev in bwrap.
190 tests on the host; probe 5/5 demonstrated.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/openultrasast/search/probe_apps/app.py.txt

@@ -7,16 +7,16 @@ import subprocess
 import sys
 import urllib.request
 
-fixed = pathlib.Path("/workspace/fixed").exists()
+fixed = (pathlib.Path(__file__).parent / "fixed").exists()
 if sys.argv[1:] == ["--ready"]:
-    sys.exit(1 if pathlib.Path("/workspace/broken").exists() else 0)
+    sys.exit(1 if (pathlib.Path(__file__).parent / "broken").exists() else 0)
 family, payload = sys.argv[1:]
 if family == "path":
     root = pathlib.Path(os.environ["SERVED_ROOT"])
     path = (root / payload).resolve()
     if not fixed or path.is_relative_to(root):
         value = path.read_text()
-        if not pathlib.Path("/workspace/flaky").exists() or value.startswith("a"):
+        if not (pathlib.Path(__file__).parent / "flaky").exists() or value.startswith("a"):
             print(value)
 elif family == "sql":
     with sqlite3.connect(os.environ["DATABASE"]) as db:
@@ -30,7 +30,7 @@ elif family == "command":
         subprocess.run("echo " + payload, shell=True, check=False)
 elif family == "ssrf":
     if not fixed:
-        print(urllib.request.urlopen(os.path.expandvars(payload), timeout=2).read())
+        print(urllib.request.urlopen((os.environ["CALLBACK_URL"] if payload == "internal" else payload), timeout=2).read())
 elif family == "xss":
     import html
     print(html.escape(payload) if fixed else payload)