Merge branch 'feat/p3-python-remote-edit' into feat/p3-wasm-swmr-python

# Conflicts:
#	CHANGELOG.md
#	docs/design/range-reads.md
#	docs/known-issues.md

README.md

@@ -574,8 +574,36 @@ with clawhdf5.File("data.h5", "r") as f:
 
     records = f["table"]               # compound -> numpy structured array
     ids = records["id"]                # one field
+
+# A file on a web server: range requests through a block cache, nothing
+# downloaded up front; the same read API. The GIL is released while waiting.
+with clawhdf5.File("http://data.example.org/run42.h5") as f:
+    first = f["group/temperatures"][0]
+f = clawhdf5.File.open_url("http://data.example.org/run42.h5", block_size=256 * 1024,
+                           headers={"Authorization": "Bearer ..."})
 ```
 
+An existing file opened with `"r+"` is edited in place (through
+`clawhdf5::FileEditor`), with h5py's indexing, broadcasting and numeric
+conversion; each edit is on disk when the statement returns:
+
+```python
+with clawhdf5.File("data.h5", "r+") as f:
+    f["group/temperatures"][100:200, ::4] = 0.0
+    f["series"].resize(5000, axis=0)   # chunked datasets, within maxshape
+    f["series"][4000:] = new_values
+    f["group"].attrs["calibrated"] = True
+```
+
+Creating or deleting datasets, groups and attributes in an existing file is
+not supported (`NotImplementedError`); limits are in
+[known issues](docs/known-issues.md).
+
+The default build reads `http://` URLs only; build with
+`maturin develop --release --features https` (rustls with ring, which
+compiles C) for `https://`, and `--features s3` (or `gcs`, `azure`) for
+object-store URLs.
+
 Reads cover integers and IEEE floats of every width in either byte order,
 `bool`, enums, complex, fixed and variable-length strings, variable-length
 sequences, opaque, HDF5 array types and compounds; other types (references,
@@ -590,7 +618,8 @@ non-default fill value (`docs/known-issues.md`). An index list is read one
 group of neighbouring chunks at a time.
 Writing (`File(path, "w")`, `create_dataset`, `create_group`, `attrs[...] =`)
 covers `float64`, `float32`, `int64`, `int32` and `uint8` arrays. The tests
-in `crates/clawhdf5-py/tests` compare every read with h5py; run them with
+in `crates/clawhdf5-py/tests` compare every read and every in-place edit
+with h5py; run them with
 `pip install pytest h5py && pytest crates/clawhdf5-py/tests`.
 
 ### Agent Memory