Merge feat/http-bearer-auth-middleware: Shared Bearer auth middleware
Implements src/server/auth.rs: bearer_auth_middleware (from_fn_with_state over
Arc<dyn IdentityProvider>, stashes Option<Identity> in request extensions),
extract_bearer_identity (Bearer-only: no/malformed/Basic/unresolvable → None,
not an error), ResolvedIdentity axum extractor. Wired into HttpAdapter router
via route_layer around gateway/openapi/mcp routes, excluding /healthz. 11 tests.
# Conflicts:
# crates/alknet-http/Cargo.toml
# crates/alknet-http/src/server/adapter.rs
# crates/alknet-http/src/server/mod.rs
glm-5.2
ccbff3c7f8