chore: release v0.6.3

[siriusctrl]

Summary

• add a dedicated CSV, TSV, and XSV field/value explorer with a searchable field sidebar and complete wrapped values
• reuse contextual search and JSON/XML/scalar highlighting inside cells while preserving exact redirected output
• keep wide files responsive with lazy logical-record indexing, bounded XSV sniffing, and bounded large-cell highlighting
• synchronize the root crate, fmtview-core, Cargo.lock, npm package, and changelog at 0.6.3

User impact

Wide delimiter-separated records no longer have to fit into a horizontal grid. Users can navigate fields in the sidebar, move between logical records, focus and search a complete payload, and inspect embedded structured content without ellipsis truncation.

Validation

• fresh independent review: no remaining findings
• cargo fmt --check
• cargo test --locked
• cargo clippy --all-targets --locked -- -D warnings
• cargo build --release --locked
• cargo publish -p fmtview-core --dry-run --locked
• npm five-file tarball dry-run, pack, temporary install, and fmtview 0.6.3 execution
• exact redirected CSV/TSV output checks
• normal and narrow real-PTY interaction/cleanup checks
• 20,000-header plus 2.2 MB raw JSON release benchmark
• Xvfb/Kitty/ffmpeg scripted interaction recording with inspected contact sheet

The root fmtview cargo dry-run packages and then reaches the expected core-first registry boundary because crates.io does not contain fmtview-core 0.6.3 yet. The tag workflow publishes core, waits for registry availability, and then verifies and publishes the root crate.