#104 Add local artifacts panel

Summary

• Add a local artifact registry that records command logs and detects generated file, patch, package, image, and export outputs from Codex command runs.
• Add /api/artifacts for per-session artifact lists, safe local downloads, and redacted manifest downloads.
• Add an Artifacts panel in chat with copy-path, safe download, refresh, and manifest actions.

Testing

• pnpm -C apps/codex-claw lint
• pnpm -C apps/codex-claw test
• pnpm -C apps/codex-claw build

Closes #91

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Summary by cubic

Adds a local artifacts registry and an Artifacts panel in chat to track files from Codex runs, with a new /api/artifacts endpoint for listing, safe downloads, and manifest export. Users can view logs, patches, images, and packages per session and download safe items.

• New Features
  • Server: records command logs and detects output files; stores size, type, timestamps, and safe-to-open flag.
  • API: /api/artifacts supports per-session lists, safe file downloads (download=1), and redacted manifest export (manifest=1).
  • Safety: only text/images from trusted paths are downloadable; all entries use redacted paths in manifests.
  • UI: new Artifacts panel in chat with refresh, copy path, download (when safe), and manifest export.
  • Client: query helpers, route tree updates, and header toggle wired to the panel.
  • Tests: coverage for redacted manifests and safe download behavior.