fix(xlsx): preserve sheet-scoped defined names

[RainLib]

What changed

• Shift definedName@localSheetId when inserting a worksheet at a logical position.
• Remap sheet-scoped names by worksheet identity when reordering sheets.
• Remove deleted-sheet scopes and clean worksheet parts, relationships, and content type overrides.
• Allocate independent unused worksheet part, sheet ID, and relationship ID values.
• Report out-of-range local sheet scopes from the issues view.
• Update the durable C# parity ledger for XLSX-001.

Why

Sheet insert, move, and remove operations could leave defined names bound to the wrong worksheet or leave dangling package references.

Validation

• cargo fmt -- --check
• cargo clippy --all-targets -- -D warnings
• cargo test --workspace
• Package tests with non-contiguous worksheet parts and IDs
• CLI smoke: create → add at index → move → remove → validate

Review stack

This PR targets feature/pptx-slide-removal-parity so its diff contains only the XLSX atomic change. Retarget it to main after the PPTX base PR merges.

[RainLib]

Independent branch validation completed because this stacked PR targets a feature branch and the pull_request workflow only listens to main. GitHub Actions run https://github.com/RainLib/OfficeCli-rust/actions/runs/29791933567 passed: format, clippy, workspace tests, and all 7 release build targets (including native smoke tests where applicable). The only annotations are the repository-wide actions/cache@v4 Node.js 20 deprecation notices.