v14.115.0 — Documentation & CI Fixes

Fixes

• MSRV — Added rust-version = "1.80" to Cargo.toml for toolchain compatibility
• Repo URLs — Updated flake.nix, CONTRIBUTING.md, and README to tiles-tui-file-manager
• README — Fixed clone dir (cd tiles-tui-file-manager), added Ctrl+Shift+T to shortcuts table
• CI — Cached cargo-audit install with actions/cache@v4 to save ~30s per run
• TODO.md — Updated stale stats (129 tests, 21,004 lines)

Install: cargo install tiles-tui-file-manager