Remove unused dependencies and narrow Tokio features

[isPANN]

Summary

Remove unused direct dependencies on ordered-float and tracing. Keep tracing-subscriber for MCP logging and let rmcp declare its own tracing dependency.

Narrow the direct Tokio features from full to rt-multi-thread, which supports the CLI runtime constructor. The existing rmcp transport-io feature supplies the required stdio support.

Only two manifests change. Dependency version requirements, Rust APIs, solver behavior, and website files are unchanged.

Validation

• cargo test --workspace --all-features --lib --bins --tests: 6,478 passed, 2 existing ignored tests; includes MCP integration tests.
• Checked source references and the all-features Tokio dependency tree.
• git diff --check passed.
• No executable source changes or new coverage-bearing lines.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 95.93%. Comparing base (7dd5fcd) to head (62e4d30).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1154   +/-   ##
=======================================
  Coverage   95.93%   95.93%           
=======================================
  Files        1074     1074           
  Lines      132106   132106           
=======================================
  Hits       126730   126730           
  Misses       5376     5376           

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[isPANN]

Consolidated into #1163. The combined dependency versions, removals, feature selection, and workspace lint command pass all-feature workspace tests and Clippy.