chore: clear rust-standards audit debt (§6.3/§6.4/§6.6/§14.5/§2.2)

[vshengbro]

Sweep of HEAD audit debt, 83 files:

• §6.3 (check 47, 203 hits): qualified std:: paths in sub-files centralized to crate roots via new skill script fix_no_qualified_std_path.py. Collision cases (bare Error vs std::io::Error struct, std::thread::Result vs prelude) demoted to module-namespace form (error::Error, io::Error, thread::Result) per §6.5. Macro-token bodies (macro_rules!/quote!) are exempt — tokens are emitted downstream, not consumed (std-macro-extensions, lombok-macros reverted accordingly).
• §6.4 (check 26, 2 hits): use std::sync::Arc; lifted from test fn bodies to tests mod.rs.
• §6.6 (check 43, 17 hits): same-root std uses aggregated into one brace form.
• §14.5 (check 30, 21 hits): comment blocks stripped from crate-cli/tests/publish/fn.rs.
• §2.2 (check 37, 9 hits): doc type literals realigned with signatures.

Gates: cargo check --workspace --all-targets rc=0, clippy 0 warnings, crate fmt idempotent + --check clean, audit 50/51 (remaining FAIL is check 49 pub-const, pre-existing debt pending a project ruling). Test totals in the PR checks.