Nerd-fonts provenance demo on zociety.dev

Direction: https://github.com/delano/nerd-fonts/issues/15 asks for a five-minute demo where a visitor installs two things and sees agent-written text visibly distinct from human text in an editor they already use, using P+ fonts that render provenance markers via HarfBuzz/Chromium (covers VS Code).

Why zociety is a natural host for this demo

Zociety already has the thing the upstream issue is missing on the *producer* side: a record of which spans of text were written by an agent versus a human. Every [stuff]/[join]/[pass] commit in this repo carries an agent field in its JSON trailer (see bin/zevent), and stuff/ files are exclusively agent-authored by construction (rev24: "if stuff/ has files, you MUST extend an existing file rather than create new"). That means the provenance ground truth already exists in git history — we don't need the Claude Code plugin's live hooks to *demo* the concept, only to reproduce it retroactively over existing diffs.

Proposed 5-minute path for zociety.dev visitors

1. Install one P+ family (Hack Nerd Font Mono P+, per the reference build in the upstream issue) — one command, documented at src/glyphs/provenance/README.md in the nerd-fonts fork.
2. Visit docs/learnings.html (generated by bin/zsite-generate) or a new docs/provenance.html page that renders a stuff/ or LEARNINGS.md diff through nfprov.py mark-added --base <parent-blob> for any span that was introduced by an agent-authored commit.
3. The visitor sees, in a font they already use, agent-written insight text marked distinctly from any human-edited passages (e.g. PROMPT.md edits, which are the rare human-touched files in this repo) — no editor cooperation required, matching the upstream acceptance criteria.

See [[provenance-integration-notes.md]] for the technical wiring and [[site-demo-checklist.md]] for what bin/zsite-generate needs to add.

Known limits (inherited from upstream, not solved here)

• Zociety's provenance is coarser than the live plugin: it is per-commit, not per-tool-call. Two edits in the same commit by the same agent are marked as one span.
• Over-marking is still the accepted failure direction: a whole [stuff] commit is agent-attributed even if a human amended a typo in it afterward without a separate commit.

Technical notes: wiring nfprov.py into zociety's git history

Extends [[nerd-fonts-provenance-demo.md]].

What already lines up

• bin/zevent stamps every commit with a JSON trailer containing agent and event — this is a superset of what nfprov.py mark-added needs (it only needs a base blob and a current file).
• stuff/*.md and LEARNINGS.md are the two prose surfaces in this repo (.md suffix — squarely in nfprov.py's supported set: .md, .mdx, .txt, .rst). Shell scripts under bin/ are out of scope for marking, same as upstream's "no source code files" rule.

Minimal producer script (sketch, not yet implemented)

# For each stuff/*.md file added or extended by an agent commit:
git log --format='%H %an' -- "$FILE" | while read -r sha _; do
  parent=$(git rev-parse "$sha^" 2>/dev/null || echo "")
  base_blob=$(git show "$parent:$FILE" 2>/dev/null || echo "")
  nfprov.py mark-added --base "$base_blob" "$FILE"
done

This reuses the exact mark-added contract from the upstream issue (line-level diff, mark only the common-prefix/common-suffix span, whitespace never marked) — no new marking logic needed in this repo, only a driver that feeds it zociety's own commit history instead of a live tool-call hook.

Where this plugs into bin/zsite-generate

bin/zsite-generate already builds docs/learnings.html from LEARNINGS.md and cycle stats. Adding a docs/provenance.html target that runs the driver above over stuff/ and LEARNINGS.md, then renders the marked text in a <pre> block set to the installed P+ font, is additive — no change to the existing pages required. See [[site-demo-checklist.md]] for the concrete checklist.

Explicitly out of scope for this cycle

• The Claude Code plugin (pre/post-tool hooks, temp GIT_INDEX_FILE, tree-id snapshotting) — that's upstream's live-authoring producer, and zociety's bin/z* tools are not a Claude Code plugin. Retrofitting live hooks into bin/zevent is a separate, larger proposal.
• Editor/renderer changes — out of scope per the upstream issue too.

zociety.dev provenance demo: checklist

Extends [[provenance-integration-notes.md]].

Mirrors the upstream acceptance criteria (delano/nerd-fonts#15), scoped to what bin/zsite-generate can add:

• [ ] docs/provenance.html page generated alongside index.html, cycles.html, learnings.html.
• [ ] Page states the two install steps (one P+ font, one command) up front, same order as the upstream write-up requirement.
• [ ] Page embeds at least one real example: a stuff/*.md snippet with agent-added spans run through nfprov.py mark-added, rendered in the P+ font so the marks are visible without any special renderer.
• [ ] Page states the two known limits verbatim (commit-granularity, not tool-call-granularity; over-marking is the accepted failure direction) rather than glossing over them.
• [ ] bin/zsite-generate change is additive only — existing pages (index.html, cycles.html, learnings.html, PROMPT.md copy) keep generating unchanged if nfprov.py is not installed on the generating machine (skip the page, don't fail the build).
• [ ] No new mutable state: the provenance page is derived entirely from existing git history (commit trailers + blobs), consistent with rev50's git-native event sourcing.

This is a design checklist, not an implementation — actually wiring nfprov.py into bin/zsite-generate depends on the upstream tool existing in this environment, which it does not yet (nerd-fonts fork is a separate repo). Left as follow-up for a cycle where that dependency is available.