fix(mkdocs): rebase cross-kind wiki links under directory URLs

Wiki pages linking to a sibling kind (for example ../lib/...) were emitted verbatim by MkDocs and, with use_directory_urls, resolved into a non-existent <kind>/<kind>/ path. Add a docforge-linkfix plugin (doc-forge 0.0.8) that rebases those links to the repository root.

docs/wiki/05_development/05_mkdocs_configs.md

@@ -55,5 +55,20 @@ Commit `docs/mkdocs.{kind}.yml` so served docs are reproducible from source.
 
 ---
 
+## 🔗 Cross-kind links
+
+Kinds are separate MkDocs sites served side by side under `/<repo>/<kind>/`,
+so a wiki page may link to the library reference with a source-relative path
+such as `../lib/13_library_registry/`. MkDocs only rewrites links that point
+inside `docs_dir`; anything reaching a sibling kind is emitted verbatim and,
+under `use_directory_urls`, resolves into `<kind>/<kind>/` and breaks.
+
+The `docforge-linkfix` plugin (part of doc-forge, enabled in the wiki
+template) fixes this at render time: it rewrites `../lib/`, `../api/`, and
+`../wiki/` links to climb to the repository root, so they resolve correctly
+however deeply the page is nested.
+
+---
+
 ## Related
 - [04 – MCP Guide](04_mcp_guide.md)