fix: decouple Python venv setup from npm install postinstall

The three Python services (PatientDataExtractorService, PaymentOCRService,
SeleniumService) provisioned their venvs via postinstall, chained into
root's own postinstall. A failure in any one of them aborted the whole
npm install, which could leave unrelated Node deps (e.g. Backend's sharp)
uninstalled — silently breaking the app with no indication why.

Renamed each service's postinstall to an explicit "setup" script, added a
root "npm run setup:python" to run all three, and documented it as its
own step in the README instead of an automatic install-time side effect.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

README.md

@@ -212,9 +212,15 @@ npm install
 
 ### Step 11 — Install Python dependencies
 
-Python dependencies are installed automatically by `npm install` (Step 10) via each service's `postinstall` script. Each service creates its own `.venv` virtual environment — no manual pip commands needed.
+```sh
+npm run setup:python
+```
 
-> This approach is required on Debian 13+ where system-wide pip installs are blocked (PEP 668).
+This creates a `.venv` virtual environment inside each Python service (`PatientDataExtractorService`, `PaymentOCRService`, `SeleniumService`) and installs its `requirements.txt` into it — no manual pip commands needed.
+
+> This venv approach is required on Debian 13+ where system-wide pip installs are blocked (PEP 668).
+
+This is a separate, explicit step rather than an `npm install` `postinstall` hook on purpose: if Python/pip setup fails on a given machine (missing system Python, no network access, a pip resolution error), it won't also abort or corrupt the Node.js dependency install for the other apps. Re-run `npm run setup:python` any time you need to rebuild these virtual envs (e.g. after moving/renaming the project folder, since venvs bake in absolute paths).
 
 ### Step 12 — Set up environment variables
 

apps/PatientDataExtractorService/package.json

@@ -2,7 +2,7 @@
   "name": "patientdataextractorservice",
   "private": true,
   "scripts": {
-    "postinstall": "python3 -m venv .venv && .venv/bin/pip install -r requirements.txt",
+    "setup": "python3 -m venv .venv && .venv/bin/pip install -r requirements.txt",
     "dev": ".venv/bin/python3 main.py"
   }
 }

apps/PaymentOCRService/package.json

@@ -2,7 +2,7 @@
   "name": "paymentocrservice",
   "private": true,
   "scripts": {
-    "postinstall": "python3 -m venv .venv && .venv/bin/pip install -r requirements.txt",
+    "setup": "python3 -m venv .venv && .venv/bin/pip install -r requirements.txt",
     "dev": ".venv/bin/python3 main.py"
   }
 }

apps/SeleniumService/package.json

@@ -2,6 +2,6 @@
   "name": "seleniumservice",
   "private": true,
   "scripts": {
-    "postinstall": "python3 -m venv .venv && .venv/bin/pip install -r requirements.txt"
+    "setup": "python3 -m venv .venv && .venv/bin/pip install -r requirements.txt"
   }
 }

package-lock.json

@@ -197,16 +197,13 @@
       }
     },
     "apps/PatientDataExtractorService": {
-      "name": "patientdataextractorservice",
-      "hasInstallScript": true
+      "name": "patientdataextractorservice"
     },
     "apps/PaymentOCRService": {
-      "name": "paymentocrservice",
-      "hasInstallScript": true
+      "name": "paymentocrservice"
     },
     "apps/SeleniumService": {
-      "name": "seleniumservice",
-      "hasInstallScript": true
+      "name": "seleniumservice"
     },
     "apps/SeleniumServiceold": {
       "name": "seleniumserviceold",

package.json

@@ -13,7 +13,8 @@
     "db:seed": "npx ts-node packages/db/prisma/seed.ts",
     "db:studio": "npx prisma studio --config=packages/db/prisma/prisma.config.ts",
     "setup:env": "shx cp packages/db/prisma/.env.example packages/db/prisma/.env && shx cp apps/Frontend/.env.example apps/Frontend/.env && shx cp apps/Backend/.env.example apps/Backend/.env && shx cp apps/PatientDataExtractorService/.env.example apps/PatientDataExtractorService/.env && shx cp apps/SeleniumService/.env.example apps/SeleniumService/.env && shx cp apps/PaymentOCRService/.env.example apps/PaymentOCRService/.env",
-    "postinstall": "npm --prefix apps/PatientDataExtractorService run postinstall && npm --prefix apps/PaymentOCRService run postinstall && bash scripts/install-rclone.sh"
+    "setup:python": "npm run setup --workspace=apps/PatientDataExtractorService && npm run setup --workspace=apps/PaymentOCRService && npm run setup --workspace=apps/SeleniumService",
+    "postinstall": "bash scripts/install-rclone.sh"
   },
   "prisma": {
     "seed": "ts-node packages/db/prisma/seed.ts"