chore(cli): pin phase 4 release tag

Bump the Harness CLI crate metadata to 0.1.5 and point installer downloads at harness-cli-v0.1.5 so benchmark installs can fetch the Phase 4 CLI release artifacts.

Validation:
- cargo fmt --check
- cargo test --workspace
- cargo clippy --workspace -- -D warnings
- bash -n scripts/install-harness.sh
- bash -n scripts/build-harness-cli-release.sh

Author: hoangbangnguyen

Cargo.lock

@@ -1,6 +1,6 @@
 [package]
 name = "harness-cli"
-version = "0.1.3"
+version = "0.1.5"
 edition.workspace = true
 license.workspace = true
 repository.workspace = true

crates/harness-cli/Cargo.toml

@@ -1 +1 @@
-harness-cli-v0.1.4
+harness-cli-v0.1.5