openarch 0.8.1 —— 后端在包里,而那条唯一的用法够不到它

[Sunrisepeak]

openarch 0.8.1 — the backend existed and the one-line usage could not reach it

0.8.0 shipped openarch-cortex-m, declared its capabilities, and exercised it
from an example that names it by PATH. The documented one-line usage is
openarch = "<version>", which goes through the backend-auto feature — a
table in the root manifest that was never extended. Measured from a fresh
project against the published 0.8.0:

error: no package provides capability 'openarch-backend' required by
       'openarch'

The package was in the tarball and unreachable through the only door a consumer
is told about.

⭐ A new capability has more readers than the site that introduced it, and the
file that BINDS it is not the file that DECLARES it. The example could not have
caught this: it uses the path, which is exactly the door a consumer lacks.

0.8.1 binds all five M-profile arch spellings — cfg(arch = ...) compares
exactly and there is no glob — and adds backend-cortex-m beside the other
named features. CI builds five fresh projects, one per spelling, whose whole
manifest is the dependency line, and requires each to compile the backend.

A/B on the tree: 0 backend compile lines before, 14 after, on every one of the
five.

0.8.0 stays listed because a published version is one someone may have pinned;
the descriptor now says why nobody should pin it on Cortex-M.

Tarball sha256 verified against the bytes and re-fetched from the CN mirror,
byte-identical. Index lints pass.