fix(wiki): resolve relative links between vault files

stacklets/memory/Dockerfile

@@ -87,6 +87,7 @@ COPY quartz/components/FamilyHead.tsx ./quartz/components/FamilyHead.tsx
 COPY quartz/components/FamilyCrumbs.tsx ./quartz/components/FamilyCrumbs.tsx
 COPY quartz/components/scripts/familyNav.inline.ts ./quartz/components/scripts/familyNav.inline.ts
 COPY quartz/plugins/familyLists.tsx ./quartz/plugins/emitters/familyLists.tsx
+COPY quartz/plugins/vaultLinks.ts ./quartz/plugins/transformers/vaultLinks.ts
 # The shipped ontology, for the topic areas a vault installed earlier
 # does not name yet (see readOntology in familyModel.ts).
 COPY seeds/ontology.toml ./ontology.seed.toml

stacklets/memory/quartz/plugins/vaultLinks.ts

@@ -0,0 +1,34 @@
+import { QuartzTransformerPlugin } from "../types"
+import { Root, Link } from "mdast"
+import { visit } from "unist-util-visit"
+import path from "path"
+
+// NEW TRANSFORMER (not an upstream override).
+//
+// The vault writes links between its own files relative to the file,
+// `[Springfield Power](../../../correspondents/springfield-power.md)`,
+// because that is the form Forgejo and Obsidian resolve. CrawlLinks runs
+// with markdownLinkResolution "absolute" (see quartz.config.ts) and reads
+// every link as a path from the vault root, `..` included, so such a link
+// lands one or more levels too high and 404s. This resolves each relative
+// link against its file's directory first and hands CrawlLinks the
+// root path it expects. A link that would climb out of the vault is left
+// as it is.
+
+const RELATIVE = /^\.\.?\//
+
+export const VaultLinks: QuartzTransformerPlugin = () => ({
+  name: "VaultLinks",
+  markdownPlugins() {
+    return [
+      () => (tree: Root, file) => {
+        const dir = path.posix.dirname(file.data.relativePath ?? "")
+        visit(tree, "link", (node: Link) => {
+          if (!RELATIVE.test(node.url)) return
+          const resolved = path.posix.normalize(path.posix.join(dir, node.url))
+          if (!resolved.startsWith("..")) node.url = "/" + resolved
+        })
+      },
+    ]
+  },
+})

stacklets/memory/quartz/quartz.config.ts

@@ -14,6 +14,7 @@
 import { QuartzConfig } from "./quartz/cfg"
 import * as Plugin from "./quartz/plugins"
 import { FamilyLists } from "./quartz/plugins/emitters/familyLists"
+import { VaultLinks } from "./quartz/plugins/transformers/vaultLinks"
 
 // Runtime env. `WIKI_HOST` is "memory.<domain>" in domain mode and
 // the empty-domain rendering "memory." in port mode — we treat the
@@ -136,6 +137,8 @@ const config: QuartzConfig = {
       Plugin.ObsidianFlavoredMarkdown({ enableInHtmlEmbed: false }),
       Plugin.GitHubFlavoredMarkdown(),
       Plugin.TableOfContents(),
+      // Relative vault links to root paths, before CrawlLinks reads them.
+      VaultLinks(),
       Plugin.CrawlLinks({ markdownLinkResolution: "absolute" }),
       Plugin.Description(),
       // MathJax, not KaTeX, and the reason is privacy rather than