CiteSource 0.2.1 — CRAN resubmission + incremental/deferred dedup

[TRileyNOAA]

Summary

Brings enhanced-dedup into dev for the CRAN 0.2.1 resubmission. This bundles the 0.2.1 feature work and the fixes for all CRAN reviewer comments on 0.2.0.

CRAN reviewer comments (0.2.0 was rejected/held — never published) — all addressed

• Title/Description formatting: Description no longer starts with "Tools for" (now leads with an active verb, "Deduplicates…"); Title already fixed; software names ('shiny', 'RIS', 'CSV') single-quoted.
• Missing \value tags: added to all 5 flagged .Rd files (and every new 0.2.1 export).
• No home-filespace writes: default filename removed from export_*(); internal write_refs() fallback writes to tempdir().

New in 0.2.1

• Incremental deduplication: dedup_citations_add_sources().
• Deferred manual review: export_dedup_candidates() / reimport_dedup_candidates() + manual_dedup_complete flag in export_csv().
• Deduplication provenance log: dedup_log().
• reimport_csv() reads all columns as character (re-dedup-safe).
• Shiny app: re-import a deduped set, add sources, content-routed multi-file re-import, source overview.
• Dropped unused networkD3 from Suggests.

Checks

R CMD check --as-cran (local, Windows, R 4.5.0): 0 errors | 0 warnings | 0 notes. Submitted to win-builder R-devel.

After merge, CRAN submission will be run from dev.