Fix npx install for Claude Code v2.1.112

Four bugs prevented `npx beastmode install` from producing a working
plugin on a clean Claude Code installation:

1. `.claude-plugin/` missing from `files` in package.json — npm strips
   it from the tarball even when fetching from GitHub, causing
   plugin-copier to fail with ENOENT.

2. index.mjs exits with code 1 on install failure but never prints the
   error message — users see only the version banner.

3. config-merger.mjs writes `source.name` in known_marketplaces.json
   but Claude Code's Zod schema requires `source.package`.

4. config-merger.mjs uses `source: "npm"` which Claude Code v2.1.112
   hasn't implemented. Additionally, plugin-copier writes
   marketplace.json to the wrong location (Claude Code expects it in a
   `.claude-plugin/` subdirectory) and the `./plugin` relative source
   path doesn't resolve.

Fixes: include `.claude-plugin/` in package files, print install errors,
use `source: "directory"` instead of `source: "npm"`, write
marketplace.json into `.claude-plugin/` subdir, and symlink the plugin
cache so the relative source path resolves.

All bugs introduced in v0.101.0 (2d84d3c). Tested from clean state on
Claude Code v2.1.112 / macOS.

Author: frosty-geek

package.json

@@ -9,7 +9,8 @@
   "files": [
     "src/npx-cli/",
     "plugin/",
-    "cli/"
+    "cli/",
+    ".claude-plugin/"
   ],
   "scripts": {
     "test:npx": "node --test src/npx-cli/__tests__/*.test.mjs",

src/npx-cli/config-merger.mjs

@@ -37,8 +37,8 @@ async function mergeKnownMarketplaces(homeDir) {
 
   data['beastmode-marketplace'] = {
     source: {
-      source: 'npm',
-      name: 'beastmode',
+      source: 'directory',
+      path: join(homeDir, '.claude', 'plugins', 'marketplaces', 'bugroger'),
     },
     installLocation: join(homeDir, '.claude', 'plugins', 'marketplaces', 'bugroger'),
     lastUpdated: new Date().toISOString(),

src/npx-cli/index.mjs

@@ -18,6 +18,9 @@ switch (command) {
       homeDir: homedir(),
       packageDir,
     });
+    if (!result.success) {
+      console.error(`Install failed at step "${result.step}": ${result.error}`);
+    }
     process.exit(result.success ? 0 : 1);
     break;
   }

src/npx-cli/plugin-copier.mjs

@@ -1,5 +1,5 @@
 // src/npx-cli/plugin-copier.mjs
-import { cp, rm, mkdir } from 'node:fs/promises';
+import { cp, rm, mkdir, symlink } from 'node:fs/promises';
 import { join } from 'node:path';
 
 /**
@@ -19,12 +19,12 @@ export async function copyPlugin({ homeDir, packageDir, version }) {
 
   // Clean-replace marketplace directory
   await rm(marketplaceDir, { recursive: true, force: true });
-  await mkdir(marketplaceDir, { recursive: true });
+  await mkdir(join(marketplaceDir, '.claude-plugin'), { recursive: true });
 
-  // Copy marketplace.json to marketplace dir
+  // Copy marketplace.json into .claude-plugin/ subdir (where Claude Code expects it)
   await cp(
     join(pluginMetaDir, 'marketplace.json'),
-    join(marketplaceDir, 'marketplace.json')
+    join(marketplaceDir, '.claude-plugin', 'marketplace.json')
   );
 
   // Clean-replace cache directory
@@ -34,6 +34,9 @@ export async function copyPlugin({ homeDir, packageDir, version }) {
   // Copy plugin tree to cache dir (includes plugin.json, skills/, agents/, hooks/)
   await cp(pluginSourceDir, cacheDir, { recursive: true });
 
+  // Symlink plugin content into marketplace dir so "source": "./plugin" resolves
+  await symlink(cacheDir, join(marketplaceDir, 'plugin'));
+
   console.log(`Plugin files copied to ${marketplaceDir}`);
   console.log(`Plugin cache written to ${cacheDir}`);
 }