Error model

Shared error kinds:

Kind	Meaning
not-found	Requested resource does not exist.
not-a-directory	Path segment expected a directory.
not-a-file	Path expected a file.
permission-denied	Provider or upstream denied permission.
invalid-input	Path, capture, config, or request input is invalid.
too-large	Requested payload is too large for this path.
network	Network or upstream transport failure.
timeout	Timed out.
denied	Host capability policy denied the request.
rate-limited	Upstream or host rate limit. May include retry-after.
version-mismatch	Cached or supplied version no longer matches.
internal	Provider or host internal failure.

Use specific errors in provider code. Avoid hiding policy denials, not-found, and rate limits inside generic internal errors.