Remove redundant package installer — let Pi handle it at runtime

Pi's own package manager already installs packages from settings.json
on first REPL launch. Feynman was duplicating this in both postinstall
and first-run, causing slow installs and looping.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "@companion-ai/feynman",
-  "version": "0.2.1",
+  "version": "0.2.2",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@companion-ai/feynman",
-      "version": "0.2.1",
+      "version": "0.2.2",
       "hasInstallScript": true,
       "dependencies": {
         "@companion-ai/alpha-hub": "^0.1.2",