Add in-app document viewer for agent and workflow artifacts

[tangemicioglu]

Problem

Wardian workflows and agents increasingly produce document-like artifacts: plans, reviews, specs, diffs, reports, transcripts, logs, and generated Markdown. Today those artifacts are mostly opened indirectly through Explorer, Source Control, terminal output, or external editors.

Wardian needs an in-app document viewer so users can inspect artifacts without losing the current agent/workflow context.

Proposed behavior

Add a reusable document viewer surface that can render at least:

• Markdown
• plain text/log files
• code files with line numbers
• diffs/patches
• JSON/YAML/TOML with readable formatting

The viewer should be embeddable from Explorer, Queue, Workflow run details, Chat/Grid transcript blocks, and Source Control where appropriate.

Acceptance criteria

• Users can open a supported local artifact in Wardian without leaving the app.
• The viewer shows path/source metadata and offers copy/open-external actions.
• Large files have a bounded loading strategy and clear truncation/error states.
• Markdown rendering is readable and does not execute unsafe embedded content.
• The component is reusable by Explorer, Queue, workflow details, and chat artifact links.

Related

• Context Inspector and Memory Routing #24 covers context segments and artifact provenance.
• Add per-block output actions: copy, filter, bookmark, and attach as context #377 covers per-block output actions.
• Render structured agent output sections for code, diffs, tables, and markdown #378 covers structured agent output rendering.