Add .env.example templates and document configuration in README

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

README.md

@@ -347,6 +347,46 @@ scores in percent.
 
 ---
 
+## Configuration (.env files)
+
+Each backend reads its credentials and paths from a `.env` file in its `backend/`
+directory. These files are gitignored — copy the `.env.example` template and fill
+in the values before running.
+
+### pgvector-demo/backend/.env
+
+```bash
+cp pgvector-demo/backend/.env.example pgvector-demo/backend/.env
+```
+
+| Variable | Description | Example |
+|---|---|---|
+| `DB_HOST` | PostgreSQL host | `localhost` |
+| `DB_PORT` | PostgreSQL host port | `5433` |
+| `DB_NAME` | Database name | `vectors_demo` |
+| `DB_USER` | Database user | `dl` |
+| `DB_PASSWORD` | Database password | — |
+| `PHOTOS_DIR` | Absolute path to the photos folder | `/home/user/photos` |
+
+### oravector-demo/backend/.env
+
+```bash
+cp oravector-demo/backend/.env.example oravector-demo/backend/.env
+```
+
+| Variable | Description | Example |
+|---|---|---|
+| `ORA_HOST` | Oracle host | `localhost` |
+| `ORA_PORT` | Oracle host port | `37611` |
+| `ORA_SERVICE` | Oracle service name (PDB) | `FREEPDB1` |
+| `ORA_USER` | User for Python-embedding backend | `vectors_user` |
+| `ORA_PASSWORD` | Password for `ORA_USER` | — |
+| `ORA_USER_INDB` | User for in-database embedding backend | `vector` |
+| `ORA_PASSWORD_INDB` | Password for `ORA_USER_INDB` | — |
+| `PHOTOS_DIR` | Absolute path to the photos folder | `/home/user/photos` |
+
+---
+
 ## Setup from scratch
 
 ### 1. PostgreSQL

oravector-demo/backend/.env.example

@@ -0,0 +1,8 @@
+ORA_HOST=localhost
+ORA_PORT=37611
+ORA_SERVICE=FREEPDB1
+ORA_USER=vectors_user
+ORA_PASSWORD=your_password
+ORA_USER_INDB=vector
+ORA_PASSWORD_INDB=your_password
+PHOTOS_DIR=/path/to/photos

pgvector-demo/backend/.env.example

@@ -0,0 +1,6 @@
+DB_HOST=localhost
+DB_PORT=5433
+DB_NAME=vectors_demo
+DB_USER=dl
+DB_PASSWORD=your_password
+PHOTOS_DIR=/path/to/photos