feat: add skill for generating MODULES.md

Author: omBratteng

.agents/skills/update-modules-doc/SKILL.md

@@ -0,0 +1,51 @@
+---
+name: update-modules-doc
+description: Scan all source modules and regenerate MODULES.md with up-to-date exports and descriptions
+---
+
+## What I do
+
+Regenerate the `MODULES.md` file at the project root so it accurately reflects every module in the package.
+
+## Steps
+
+1. **Scan entry points** — Find all `.ts` files matching `src/*/*.ts` (excluding `src/types/`). Each file is a module entry point.
+2. **Read each file** — For every entry point, identify all named exports and their types/signatures. Read JSDoc comments to extract descriptions.
+3. **Regenerate `MODULES.md`** — Overwrite the file using the exact format below. Modules should be listed in alphabetical order by their import path.
+
+## Output format
+
+The file must follow this exact structure:
+
+```markdown
+# Modules
+
+All modules are importable via subpath exports from `@dailydotdev/node-common`.
+
+## <directory>/<filename>
+
+**Import:** `@dailydotdev/node-common/<directory>/<filename>`
+
+<Brief description of what this module provides, derived from JSDoc or file contents.>
+
+| Export         | Type               | Description                          |
+| -------------- | ------------------ | ------------------------------------ |
+| `<exportName>` | `<type signature>` | <description from JSDoc or inferred> |
+```
+
+Repeat the `## <directory>/<filename>` section for each module.
+
+## Rules
+
+- The module heading uses the path relative to `src/` without the `.ts` extension (e.g., `utils/env`, `logger`).
+- If the filename is `index`, omit it from the heading and import path (e.g., `src/logger/index.ts` becomes `logger`, not `logger/index`).
+- The import path is `@dailydotdev/node-common/<directory>/<filename>` (e.g., `@dailydotdev/node-common/utils/env`, `@dailydotdev/node-common/logger`).
+- If a module has behavioral notes (e.g., environment-dependent behavior), include a bullet list below the description and above the exports table.
+- Only include files that have at least one export. Skip empty files or files with no exports.
+- Do not include files under `src/types/` — those are ambient type declarations, not importable modules.
+- Always sort modules alphabetically by import path.
+- Always sort exports alphabetically within each module.
+
+## When to use me
+
+Use this skill whenever a new module is added, an existing module's exports change, or a module is removed. This keeps `MODULES.md` in sync with the source code.