feat: generate devlog index page

- rename build-wisp-docs.mjs -> build-site.mjs
- generate devlog/index.md listing all entries (newest first)
- header link now goes to devlog index instead of specific entry

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <[e-mail]>

.tangled/workflows/deploy-docs.yml

···
   WISP_SITE_NAME: "docs"
 
 steps:
-  - name: build docs site
+  - name: build site
     command: |
-      bun ./scripts/build-wisp-docs.mjs
+      bun ./scripts/build-site.mjs
 
   - name: deploy docs to wisp
     command: |

scripts/build-wisp-docs.mjs scripts/build-site.mjs

···
     }
   }
 
-  // Copy devlog files to docs/devlog/ (accessible via SPA but not in sidebar)
+  // Copy devlog files to docs/devlog/ and generate an index
   const devlogFiles = (await exists(devlogDir)) ? await listMarkdownFiles(devlogDir) : [];
+  const devlogEntries = [];
+
   for (const rel of devlogFiles) {
     const src = path.join(devlogDir, rel);
     const dst = path.join(outDocsDir, "devlog", rel);
     await mkdir(path.dirname(dst), { recursive: true });
     await cp(src, dst);
+
+    const md = await readFile(src, "utf8");
+    devlogEntries.push({
+      path: `devlog/${rel}`,
+      title: titleFromMarkdown(md, rel),
+    });
+  }
+
+  // Generate devlog index listing all entries (newest first by filename)
+  if (devlogEntries.length > 0) {
+    devlogEntries.sort((a, b) => b.path.localeCompare(a.path));
+    const indexMd = [
+      "# devlog",
+      "",
+      ...devlogEntries.map((e) => `- [${e.title}](${e.path.replace("devlog/", "")})`),
+      "",
+    ].join("\n");
+    await writeFile(path.join(outDocsDir, "devlog", "index.md"), indexMd, "utf8");
   }
 
   // Stable nav order: README homepage, then roadmap, then changelog, then the rest.

site/index.html

···
         </button>
         <a class="brand" href="./">zat.dev</a>
         <div class="header-links">
-          <a class="header-link" href="#devlog/001-self-publishing-docs.md">devlog</a>
+          <a class="header-link" href="#devlog/index.md">devlog</a>
           <a class="header-link" href="https://tangled.sh/zat.dev/zat" target="_blank" rel="noopener noreferrer">repo</a>
         </div>
       </header>