Make local server metadata atomic and concurrency-safe

[sdairs]

Summary

• write local server metadata through unique sibling temporary files with full writes, flush/sync, and atomic rename
• serialize ClickHouse and Postgres lifecycle, recovery, removal, and stale-PID normalization with per-server cross-process locks so stale state cannot overwrite a restart
• preserve selected metadata read, permission, parse, and write failures as distinct actionable human and structured errors
• add deterministic corruption, invalid UTF-8, permission, interrupted-write, concurrent lifecycle/client/stop, and stale-normalization/restart coverage

Closes #472

Tests

• cargo fmt --all --check
• cargo build -p clickhousectl
• cargo check -p clickhousectl --no-default-features
• cargo test -p clickhousectl
• cargo clippy -p clickhousectl --all-targets -- -D warnings

Stack

• Position: child 8 of 8 in gh-stack #489
• Base: Make omitted local server selection deliberate #514 (issue-473-omitted-server-selection)
• Parent PR is unchanged and should merge first.

[cursor]

Cursor Bugbot has reviewed your changes using high effort and found 1 potential issue.

There are 2 total unresolved issues (including 1 from previous review).

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