feat(wiki): docs-lookup plugin against Quartz contentIndex

New maubot plugin that points at any Quartz-rendered docs site and
answers chat queries by full-text searching its emitted
/static/contentIndex.json. Default config targets docs.ariege.io
(castle-docs).

Commands:
  !ask <query>            search corpus; top-N hits with snippet + link
  !doc <slug-or-title>    open a specific page (fuzzy title match)
  !wiki / !wiki refresh   status / force re-index

Architecture:
- Periodic fetch (default 10 min) of /static/contentIndex.json
- In-memory inverted-ish scoring: title hit 5pt, content hit 1pt + freq
- No LLM — pure deterministic keyword search; RAG is future Phase 2b
- No DB — index is upstream-derived cache, repopulates on bot restart

Deployment posture: docs.ariege.io is served from cfaun alongside
maubot, so the bot hits it over the host's internal network — works
during WAN outages. base-config.yaml exposes docs_url + index_path
for adopters pointing at their own site.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

wiki/README.md

@@ -0,0 +1,117 @@
+# wiki
+
+Documentation-lookup Matrix bot. Points at any
+[Quartz](https://quartz.jzhao.xyz/)-rendered docs site, periodically
+fetches its `contentIndex.json`, and answers queries in chat.
+
+Designed to be community-portable — works against any Quartz site you
+configure it for, not just `docs.ariege.io`. Adjust `docs_url` per
+instance.
+
+## Commands
+
+```
+!ask <question>           # full-text search the docs, top 3 with snippets
+!doc <slug-or-title>      # open a specific page (exact slug or fuzzy title)
+!wiki                     # status: doc count, last refresh, source URL
+!wiki refresh             # force re-index now (admin nicety)
+```
+
+## Examples
+
+```
+!ask how do I shut the water off
+!ask alpaca feeding winter
+!ask power outage
+!doc emergency/water-emergency
+!doc water emergency           # fuzzy title match works too
+!wiki                          # are we up to date?
+```
+
+The bot replies with markdown links to the doc pages, so clicking
+through opens the full doc in a browser.
+
+## How it works
+
+Quartz emits `/static/contentIndex.json` as part of its standard build
+— a flat `{slug: {title, content, tags}}` map of every published page.
+The plugin fetches that file on a timer (default every 10 minutes),
+keeps an in-memory inverted index, and scores searches by:
+
+- Title hits: 5 points each
+- Content hits: 1 point + 0.1 × frequency
+
+Top N (default 3) results come back with a short snippet around the
+first match. **No LLM is involved** in v1 — pure deterministic keyword
+search. Phase 2b / future work may add an LLM synthesis step (RAG)
+once the inference layer is up.
+
+## Config
+
+`base-config.yaml` (override per maubot instance from the UI):
+
+```yaml
+docs_url: https://docs.ariege.io        # Quartz site base URL
+index_path: /static/contentIndex.json   # standard Quartz path
+refresh_minutes: 10                     # re-fetch cadence
+max_results: 3                          # !ask hit limit
+snippet_chars: 160                      # snippet window
+site_name: Castle Docs                  # human-readable label in output
+```
+
+For internal-network deployments (the recommended posture — see below),
+set `docs_url: http://<internal-hostname>` instead of the public URL.
+
+## Deployment posture (Château du Faune)
+
+Both `docs.ariege.io` and the maubot daemon run on **cfaun**. The bot
+hits the docs site over the host's loopback / internal network, so:
+
+- No WAN dependency — the bot works during internet outages
+- The fetch is fast (no TLS handshake to the public internet)
+- If `docs.ariege.io` is down externally, the bot is unaffected
+- Same applies if a future inference node (e.g. a ZeroClaw box) lives
+  on the internal network: it can hit the same internal URL
+
+If you're deploying elsewhere, point `docs_url` at whichever URL the
+bot's host can actually reach.
+
+## Build + iterate
+
+```sh
+cd ~/dev/maubot-plugins/wiki
+zip -j ../wiki.mbp maubot.yaml base-config.yaml *.py
+```
+
+Upload via maubot UI → Plugins → click existing → upload new `.mbp`.
+**Hit Save on the instance** after upload (the standard maubot
+facepalm). For a new instance, edit the config to point at your docs
+site and save.
+
+## Known limitations (v1)
+
+- **No LLM synthesis.** Returns matched passages, not a synthesized
+  answer. RAG (`!ask` → cited synthesized answer) is the natural Phase
+  2b enhancement when the inference node is live.
+- **Stopwords are minimal.** A query like "how do I" mostly matches
+  stopwords and may return weak results — phrase queries with the
+  actual content words ("water shutoff", "winter feeding").
+- **No spell correction on content terms.** Title fuzzy match works
+  for `!doc`; for `!ask` you need to spell the keywords correctly.
+- **No personalization.** Everyone in the room sees the same hits.
+- **No multi-site support per plugin instance.** One Quartz site per
+  maubot instance — to serve a second docs source, install a second
+  instance with a different config.
+
+## Adopting for a different docs site
+
+This plugin is intentionally protocol-agnostic at the content layer —
+anything that emits a `{slug: {title, content}}` JSON map will work.
+For non-Quartz docs sites, you can either:
+
+1. Adapt the upstream build to emit a compatible `contentIndex.json`
+2. Fork this plugin's `_refresh()` to parse your site's index shape
+
+Common alternates worth considering for adopters: MkDocs (with the
+mkdocs-material search plugin), Docusaurus, mdBook, or a custom
+generator.