Allow direct local client connections to select a binary version

[sdairs]

Summary

• add direct-only local client --version <exact-installed-version> binary selection without changing the configured default
• retain default-only resolution when direct --version is omitted, with no zero/one/multiple-install guessing and actionable missing/stale errors
• preserve named-server metadata version selection and document connection selection separately from local binary selection
• cover the parser and subprocess default/installed/explicit-version matrices

Closes #469

Verification

• cargo fmt --all --check
• cargo build -p clickhousectl
• cargo test -p clickhousectl (756 passed)
• cargo clippy -p clickhousectl --all-targets -- -D warnings

Stack

• Position: child 4 of 4 in gh-stack #489
• Base: Validate local client selectors and ports #492 (issue-466-local-client-selectors)
• Parent PR is unchanged and should merge first.

[sdairs]

good but adds too much noise to agent context help. it is unlikely that thorough explanation of a --version flag is needed beyond the actual flag description

[sdairs]

Addressed in 30c6f10: removed the redundant --version explanation from agent-context help, restored the existing concise connection/default wording, and retained the flag and its description. Verified with the focused help test, the local client selector integration suite, cargo fmt --all --check, cargo check -p clickhousectl, and clippy with warnings denied.

[iskakaushik]

LGTM

[sdairs]

Superseded by #552 in stack #563.