NK-WP-0058-T02 step 2: T15 and T19 exercises run in the contract CI

T19 runs the KeyCape binary from the pinned image instead of docker: tools/contract-tests/oci_extract.py
pulls the image anonymously by digest and verifies manifest and layer digests before extracting.
Both exercises record GITHUB_SHA when net-kingdom is a source tarball. PyJWT[crypto] chain pinned by
PyPI-checked hashes. 85 tests pass in a CI-like layout. rapp CI recorded (rapp 15df0e3).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Assistant: claude-code
Assistant-Model: opus
Assistant-Process: 943911@bnt-lap001
Assistant-Session: fc322940-1c8e-4bed-ab39-86cec99f23a0

docs/bounded-execution-contract-table.md

@@ -505,7 +505,7 @@ The agent's default context can read NetworkPolicies in `sso`, `approval-engine`
 | railiance-platform | `a2105e34` | open |
 | key-cape | `ee1e5bb5` | open |
 
-- **Open, founder:** rapp-bounded-executor is private, so net-kingdom CI cannot fetch it without a credential, and
-  the rapp has no CI of its own. Its packaging tests (E8 ceiling, E9 egress, R2 config and exit codes) run only
-  locally today. The options are a rapp CI workflow, which needs the runner to read a private repository, or
-  making the rapp public.
+- **rapp-bounded-executor (private):** it tests itself in its own CI since 2026-11-06 (founder choice, rapp
+  `15df0e3`, `.forgejo/workflows/packaging.yaml`). The run fetches its own tarball with the run's automatic
+  repository-scoped token, clones net-kingdom and railiance-platform anonymously at `main`, and fails on any skip.
+  That covers E8 (ceiling), E9 (egress) and R2 (config, exit codes), on push and nightly.