chore: add fallow + clean up dead code and duplication

.agents/skills/author-recipes-and-cookbooks/SKILL.md

@@ -61,7 +61,7 @@ All three are registered in `src/lib/recipes/recipes.ts`, share a flat `/templat
    - add an entry to `cookbooks` with `id`, `name`, `description`, `recipeIds`
    - rely on `createCookbook()` to derive `tags` and `services`
 4. Create `src/pages/templates/<slug>.tsx` following the existing pattern:
-   - import `CookbookDetail`, `cookbooks`, `useAllRawRecipeMarkdown`
+   - import `CookbookDetail`, `cookbooks`, `useAllRecipeSections`, `useCookbookIntro`, and `composeCookbookMarkdown`
    - import each recipe markdown module from `@site/content/recipes/<slug>/content.md`
    - select the cookbook with `cookbooks.find((c) => c.id === "<slug>")`
    - build `rawMarkdown` from `cookbook.recipeIds` joined with `\n\n---\n\n`

.fallowrc.json

@@ -0,0 +1,28 @@
+{
+  "$schema": "https://raw.githubusercontent.com/fallow-rs/fallow/main/schema.json",
+  "ignorePatterns": ["examples/**", "content/**", ".docusaurus/**", "build/**"],
+  "ignoreDependencies": [
+    "@modelcontextprotocol/sdk",
+    "@docusaurus/module-type-aliases",
+    "@docusaurus/tsconfig",
+    "mdast",
+    "mdast-util-mdx",
+    "unified",
+    "unist",
+    "unist-util-visit",
+    "prism-react-renderer"
+  ],
+  "ignoreExports": [
+    {
+      "file": "api/mcp.ts",
+      "exports": ["GET", "POST", "DELETE"]
+    },
+    {
+      "file": "src/components/ui/**",
+      "exports": ["*"]
+    }
+  ],
+  "rules": {
+    "unused-dependencies": "warn"
+  }
+}

.gitignore

@@ -39,3 +39,4 @@ examples/**/.databricks/
 # Screenshots
 /screenshots
 .vercel
+.fallow/

AGENTS.md

@@ -16,6 +16,7 @@ For every change to DevHub, do the following:
 - run `npm run fmt` to format the code
 - run `npm run typecheck` to verify types are correct
 - run `npm run verify:images` to verify example/resource images (16:9, ≥1600x900) when you've added or changed anything under `static/img/examples/`
+- run `npx fallow dead-code` and `npx fallow dupes` to check for dead code and duplication after your changes (see "Dead Code & Duplication" below)
 - use agent-browser to verify the changes
 - use the `seo-audit` skill to verify all changes are SEO-friendly
 - use the `frontend-design` skill to verify all changes adhere to the design principles
@@ -59,6 +60,35 @@ This repository uses **npm** exclusively. Do not use bun, yarn, or pnpm. All scr
 - Use brand colors and avoid raw color values
 - Always use shadcn/ui components as the foundation for all UI
 
+## Dead Code & Duplication
+
+After making changes, always run [fallow](https://github.com/fallow-rs/fallow) to keep the codebase clean:
+
+```bash
+npx fallow dead-code
+npx fallow dupes
+```
+
+Then reason from first principles before acting on the report — do not blindly delete or merge:
+
+### Dead code (`fallow dead-code`)
+
+For every flagged item, decide between two options:
+
+- **Remove it** if the code is genuinely unreachable, no longer referenced, or was scaffolding that never got wired up.
+- **Wire it up** if the code is something the change you just made should actually be using (e.g. you wrote a parallel implementation and forgot the existing helper). In that case, leverage the existing code instead of duplicating it.
+
+Always prefer the simpler outcome: a smaller codebase with no orphaned exports.
+
+### Duplication (`fallow dupes`)
+
+Duplication reports are a hint, not a verdict. For each cluster:
+
+- **Ignore it** when the matches are not _real_ duplicates — e.g. similar shapes that happen to look alike, generated code, fixtures, or two functions that share a structure but model genuinely different concepts. Some repetition is good; premature abstraction is worse than a little copy-paste.
+- **Unify it** only when the matches are clearly the same type, the same function, or the same logic expressed twice. In that case, extract a shared helper / type / component and replace the call sites.
+
+When in doubt, leave it alone and write a short note in the PR explaining why the duplication is intentional.
+
 ## Browser Automation
 
 Use `agent-browser` for web automation. Run `agent-browser --help` for all commands.

api/content-markdown.ts

@@ -5,10 +5,10 @@ import { ABOUT_DEVHUB_SLUG } from "../src/lib/bootstrap-prompt";
 import {
   hasContentSlug,
   hasSolutionSlug,
-  joinContentSections,
   readContentSections,
   readCookbookIntro,
 } from "../src/lib/content-markdown";
+import { joinContentSections } from "../src/lib/content-sections";
 import { buildCookbookMarkdownDocument } from "../src/lib/cookbook-composition";
 import { expandMdxImports } from "../src/lib/expand-mdx";
 import {

package.json

@@ -32,15 +32,13 @@
     "@docusaurus/core": "3.9.2",
     "@docusaurus/preset-classic": "3.9.2",
     "@docusaurus/theme-mermaid": "3.9.2",
-    "@hookform/resolvers": "^5.2.2",
     "@mdx-js/react": "^3.0.0",
     "@modelcontextprotocol/sdk": "^1.25.2",
     "@vercel/analytics": "^2.0.1",
     "@vercel/functions": "^3.4.3",
     "class-variance-authority": "^0.7.1",
     "clsx": "^2.0.0",
     "cmdk": "^1.1.1",
-    "date-fns": "^4.1.0",
     "docusaurus-lunr-search": "3.6.0",
     "embla-carousel-react": "^8.6.0",
     "input-otp": "^1.4.2",
@@ -67,6 +65,7 @@
     "@playwright/test": "^1.58.2",
     "@tailwindcss/postcss": "^4.2.2",
     "@vercel/node": "^5.6.15",
+    "fallow": "^2.45.0",
     "husky": "^9.1.7",
     "image-size": "^2.0.2",
     "postcss": "^8.5.8",

plugins/content-entries.ts

@@ -4,10 +4,12 @@ import type { LoadContext, Plugin } from "@docusaurus/types";
 import {
   getContentSlugs,
   getSolutionSlugs,
-  joinContentSections,
   readContentSections,
-  type ContentSections,
 } from "../src/lib/content-markdown";
+import {
+  joinContentSections,
+  type ContentSections,
+} from "../src/lib/content-sections";
 import {
   recipes,
   examples,

plugins/cookbooks.ts

@@ -5,7 +5,7 @@ import {
 } from "../src/lib/content-markdown";
 import { cookbooks } from "../src/lib/recipes/recipes";
 
-export type CookbooksGlobalData = {
+type CookbooksGlobalData = {
   /** Raw `content/cookbooks/<slug>/intro.md` bodies keyed by cookbook id. */
   introsBySlug: Record<string, string>;
 };

plugins/robots-txt.ts

@@ -37,5 +37,3 @@ export default function robotsTxtPlugin(context: LoadContext): Plugin {
     },
   };
 }
-
-export { buildRobotsTxt };