Add native work-level integrity scanning with shared status taxonomy

[jnton]

Parent program: mdpi-filter/mdpi-filter-chrome roadmap issue.

Goal

Extend the Zotero plugin from MDPI venue/reference detection to formal work-level integrity signals while keeping the two concepts separate in UI, tags, and data flow.

Status taxonomy

• retracted or partially retracted;
• expression of concern;
• corrected/corrigendum/erratum;
• reinstated/retraction reversed;
• withdrawn/removed;
• duplicate-publication finding.

Workflows

• Scan the selected item, collection, saved search, or entire library.
• Resolve item DOI first; use PMID/PMCID only as identifier-resolution fallback.
• Scan references in attached PDFs/HTML where reliable identifiers are available.
• Show chronology and source provenance in a dedicated pane/dialog.
• Apply structured tags in a reserved namespace, with an option to disable tagging.
• Rescan stored items when the evidence bundle version changes.
• Produce a bibliography integrity report before manuscript submission.
• Never overwrite user notes or unrelated tags.

Data and privacy

• Consume the same normalized evidence bundle as browser clients.
• Permit optional direct Crossref/Europe PMC refresh with explicit user control.
• Transmit identifiers only, never attachment text or library metadata unrelated to lookup.
• Keep network lookups disabled when the existing network preference is off.
• Cache by normalized DOI and evidence-bundle version.

Compatibility

• Preserve the current add-on ID and update channel.
• Keep MDPI tags/warnings distinct from formal article-status tags.
• Remain compatible with supported Zotero 7–9 versions.

Tests

• current retraction;
• concern followed by retraction;
• retraction followed by reinstatement;
• correction-only item;
• duplicate-publication reason;
• opt-out causing zero HTTP requests;
• DOI normalization and duplicate item handling;
• no tag/note corruption;
• selected collection and full-library scans;
• runtime tests inside Zotero.

Release gate

Do not promote through Zotero Forums until a signed release, update manifest, privacy documentation, runtime test transcript, and public benchmark report are available.