ci: auto-sync GitHub wiki module pages from man pages

Add tooling that makes the scdoc man pages the single source of truth and
regenerates the wiki module pages from them:

- .github/wiki/mapping.json: man-page -> wiki-page mapping (aggregation-aware)
- .github/wiki/generate.py: scdoc -> pandoc -> gfm, strips man-only sections,
  concatenates aggregated pages, appends optional extras/<Page>.md
- .github/wiki/extras/: hand-kept appendices (screenshots) with no man equivalent
- .github/workflows/wiki.yml: on push to man/** (or the tooling), regenerate
  and push the wiki; other wiki pages are left untouched

Covers all 65 man pages -> 45 wiki pages (5 new: GPS, Inhibitor, Mango, Menu,
WWAN). Non-module and hand-written wiki pages are never modified.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.github/wiki/README.md

@@ -0,0 +1,42 @@
+# Wiki sync
+
+The scdoc man pages under [`man/`](../../man) are the **single source of truth**
+for module documentation. The GitHub wiki module pages are generated from them by
+[`generate.py`](generate.py) and kept in sync automatically by the
+[`wiki.yml`](../workflows/wiki.yml) workflow on every push to `master` that
+touches `man/**` or this tooling.
+
+## Files
+
+- `mapping.json` — maps each wiki page to the ordered list of man-page basenames
+  that compose it. Several man pages are concatenated into one aggregated page
+  (e.g. `Module:-Hyprland` ← the four `waybar-hyprland-*` pages). **Add an entry
+  here when you add a new man page** — the workflow fails the mapping check
+  otherwise.
+- `generate.py` — `scdoc → roff → pandoc → gfm`, strips the `NAME`/`FILES`/`AUTHOR`
+  man sections, and writes one `Module:-*.md` per mapping entry.
+- `extras/<Page>.md` — optional hand-maintained appendix (screenshots, showcase
+  snippets that have no man equivalent), appended verbatim after the generated body.
+
+## What it touches
+
+Only the pages listed in `mapping.json` are (re)written. Every other wiki page
+(`Home`, `Installation`, user showcases, the hand-written `Module:-Cava:-GLSL`,
+`Module:-Group`, `Module:-Load`, …) is left untouched.
+
+## To edit a module's docs
+
+Edit the man page under `man/`, not the wiki. The wiki page is overwritten on the
+next sync. Put anything with no man equivalent (images, etc.) in `extras/`.
+
+## Run locally
+
+```sh
+python3 .github/wiki/generate.py --check                 # validate mapping only
+python3 .github/wiki/generate.py --out-dir /tmp/wiki-out # generate a preview
+```
+
+## One-time setup
+
+The repository wiki must be enabled (Settings → Features → Wikis) with at least
+one initial page so the `.wiki.git` remote exists.