Revert the capability set, and say what isolated mode bounds

CHANGELOG.md

@@ -1,30 +1,5 @@
 # Changelog
 
-## 5.1.0 (unreleased)
-
-### Added
-
-- **Capabilities for isolated children** - `py_context:new(#{mode => isolated,
-  caps => ...})` names the directories, environment variables and network
-  addresses a child may reach; anything not named is refused. Leaving a key
-  out grants none of it, and omitting `caps` leaves existing behaviour
-  unchanged. Paths are resolved a component at a time with `openat` and
-  `O_NOFOLLOW` from the descriptor of the grant, so `..`, absolute paths,
-  symlinks out of a grant and symlinked directory prefixes are all refused,
-  and refusals are `PermissionError` rather than `FileNotFoundError` so they
-  disclose nothing about what exists outside. Network rules name addresses
-  and never host names, resolution is its own capability covering every
-  resolver, and binding is checked against `listen` rather than `connect`.
-  Process creation, `ctypes`, signals to another process and Unix-socket
-  addresses are refused outright. The model and its vocabulary come from
-  erlang_wasm's WASI implementation.
-
-  This is a cooperative policy over Python and not a boundary: it is built
-  on a CPython audit hook, so it binds Python and not a C extension, and it
-  covers only what CPython announces. `docs/capabilities.md` says what holds
-  and what does not. Shared memory and capability sets do not combine yet,
-  because a region reaches the child as a path.
-
 ## 5.0.0 (2026-08-29)
 
 ### Added

README.md

@@ -622,21 +622,14 @@ When creating Python contexts, you can choose the execution mode:
 %% segfault only takes the child down, rlimits bound memory and CPU.
 {ok, Ctx} = py_context:new(#{mode => isolated, kill_after => 1000,
                              rlimits => #{as => 512 * 1024 * 1024}}).
-
-%% Name what the child may reach, and it reaches nothing else.
-{ok, Ctx} = py_context:new(#{mode => isolated,
-                             caps => #{dirs => [{"/srv/models", read}],
-                                       net  => #{connect => [{tcp, <<"10.0.0.0/8">>, 5432}]}}}).
 ```
 
 **Isolated mode** is the only mode with a hard bound: `py_context:interrupt/1`
 stops a blocking C call, and `SIGKILL` is the backstop. It costs a process per
 context (about 16 MB and 40 ms to start) and roughly twice the call latency.
 Bulk data crosses through shared memory (`py_shm`, with the optional
-[iommap](https://hex.pm/packages/iommap) dependency), and the `caps` option
-names the files, addresses and environment the child may reach, as a
-cooperative policy over Python rather than a kernel boundary. See
-[Isolated Contexts](docs/isolated.md) and [Capabilities](docs/capabilities.md).
+[iommap](https://hex.pm/packages/iommap) dependency). See
+[Isolated Contexts](docs/isolated.md).
 
 **Worker mode is recommended** because it works with any Python version and automatically benefits from free-threaded Python (3.13t+) when available. Each context owns a dedicated pthread, providing stable thread affinity for libraries with thread-local state (numpy, torch, tensorflow).
 

docs/code-map.md

@@ -29,7 +29,6 @@ exercised by suites). Guides are in `docs/`, suites in `test/`. Start with
 | `py_channel`, `py_byte_channel` | Term and byte queues between Erlang and Python coroutines (NIF resources) | live | channel | `py_channel_SUITE`, `py_byte_channel_SUITE` |
 | `py_buffer` | Native streaming input buffer; shared variant delegates to `py_shm` | live | buffer, isolated | `py_buffer_SUITE`, `py_isolated_buffer_SUITE` |
 | `py_shm` | Shared memory regions over iommap and the ring behind shared buffers | live | isolated | `py_isolated_shm_SUITE` |
-| `py_caps` | The `caps' option: what an isolated child may reach, and its wire form | live | capabilities | `py_isolated_caps_SUITE` |
 | `py_import` | Registry of imports and `sys.path` entries applied to every interpreter | live | imports | `py_import_SUITE` |
 | `py_preload` | Code run once per interpreter at start | live | preload | `py_preload_SUITE` |
 | `py_state` | Shared key/value store visible from Python as `erlang.state_get/set/delete/keys` | live | README (shared state) | `py_state_SUITE` |
@@ -81,7 +80,6 @@ loop, channels and servers.
 | `_erlang_impl/_etf.py` | Pure-Python ETF codec with the `py_convert.c` mapping | isolated child |
 | `_erlang_impl/_isolated.py` | Child runtime: socket frames, reader thread, re-entrant main loop, interrupt signal, asyncio loop, the `erlang` shim | isolated child |
 | `_erlang_impl/_shm.py` | `SharedMemory` and `SharedBuffer` wrappers over mmap | all |
-| `_erlang_impl/_caps.py` | Capability enforcement in the child: path containment, address matching, the audit hook | isolated child |
 | `py_isolated_child.py` | Child launcher: rlimits, parent-death signal, cgroup join, connect | isolated child |
 | `test_erlang_loop.py`, `test_async_task.py`, `test_channel_ref.py`, `tests/` | Python-side tests of the loop, tasks and channels | test |