feat: alkcall 0.9.0 adoption — bump to 0.7.0

The stub-sweep release changes no type alktty touches: the four
implemented stubs, the register_openable Pub-typed refusal (alktty's
op is Sub-typed), the register_imported Result return, and the removed
RelayError::PubTypedOpen are all surfaces alktty never exercises.

- alkcall requirement 0.8.1 -> 0.9.0; lockfile follows
- alktty 0.6.0 -> 0.7.0 (minor: raising the minimum alkcall requirement
  is ecosystem-coordination breaking on a 0.x crate)
- one test fix: `establisher_ok_on_valid_params` formatted a
  Result<Establishment, _> with {:?} — Establishment no longer derives
  Debug in alkcall 0.9.0; the assert now branches on Err and formats
  only the error

Verification: 113 default / 156 all-features tests, clippy
--all-targets -D warnings, fmt --check, cargo doc, fuzz corpus replay
(9 tests / 340 seeds), wasm32-unknown-unknown check + clippy,
publish --dry-run — all pass.

fuzz/Cargo.lock

@@ -27,9 +27,9 @@ dependencies = [
 
 [[package]]
 name = "alkcall"
-version = "0.8.1"
+version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bf6af1e4af1460480849adf959c972d65deeafc36f4101064ced1ce6d1adfd5b"
+checksum = "a3562f1f7b348cdeb3d9181eaf57b0a2fb3f988d4280e8e225dadfd7f763cb84"
 dependencies = [
  "async-trait",
  "bytes",
@@ -48,7 +48,7 @@ dependencies = [
 
 [[package]]
 name = "alktty"
-version = "0.5.0"
+version = "0.7.0"
 dependencies = [
  "alkcall",
  "async-trait",