refactor(tools): rename rhema-tools-contract to rhema-claw-tools-contract

The crate binds the claw to its client tools, not tools at large,
so it carries the claw's name: package, lib and dep names, the
mock's binary, and the conformance suite's use paths. Specs and
README follow. The tools/contract directory keeps its name, and
no reference to the old name remains.

crates/rhema-claw/Cargo.toml

@@ -49,7 +49,7 @@ rhema-rsd = { path = "../rhema-rsd" }
 # The tool contract: the agent-token allowlist and version the auth
 # middleware enforces (rhema-tools spec). The arrow runs claw ->
 # contract only — never the reverse.
-rhema-tools-contract = { path = "../../tools/contract" }
+rhema-claw-tools-contract = { path = "../../tools/contract" }
 # The resident tier's durable memory: its tools join the resolver chain
 rhema-memory = { path = "../rhema-memory" }
 # The shared ModelCard the backend registry's listings return