feat: add Paperclip env example file with placeholder secrets

Add env/.env.example.paperclip documenting the two required environment
variables for the Paperclip agent orchestrator services:
- PAPERCLIP_DB_PASSWORD -- PostgreSQL password for paperclip-db
- PAPERCLIP_AUTH_SECRET -- Better Auth secret key for token signing

Users copy this to .env and fill in the secrets before deploying.

ai/Dockerfile

@@ -15,11 +15,7 @@ ENV PLAYWRIGHT_BROWSERS_PATH=/opt/hermes/.playwright
 RUN apt-get update && \
     apt-get install -y --no-install-recommends \
         build-essential nodejs npm python3 ripgrep ffmpeg gcc python3-dev libffi-dev procps git openssh-client docker-cli tini \
-        curl poppler-utils imagemagick \
-        chromium xvfb fonts-noto-color-emoji fonts-unifont fonts-liberation fonts-ipafont-gothic fonts-wqy-zenhei fonts-tlwg-loma-otf fonts-freefont-ttf \
-        libasound2t64 libatk-bridge2.0-0t64 libatk1.0-0t64 libatspi2.0-0t64 libcairo2 libcups2t64 libdbus-1-3 libdrm2 libgbm1 libglib2.0-0t64 libnspr4 libnss3 libpango-1.0-0 libx11-6 libxcb1 libxcomposite1 libxdamage1 libxext6 libxfixes3 libxkbcommon0 libxrandr2 \
-        texlive-latex-base texlive-latex-extra texlive-fonts-recommended texlive-xetex texlive-science \
-        qemu-user-static binfmt-support qemu-user-binfmt && \
+        curl poppler-utils imagemagick && \
     rm -rf /var/lib/apt/lists/*
 
 # Non-root user for runtime; UID can be overridden via HERMES_UID at runtime

env/.env.example.paperclip

@@ -0,0 +1,26 @@
+# Paperclip Environment Variables
+# Copy this file to your .env (at the compose root or docker-compose working directory)
+# and fill in the secrets.
+#
+#   cp env/.env.example.paperclip .env
+#
+# Then reference it from compose.yml:
+#   env_file:
+#     - path: .env
+#       required: true
+
+# ---------------------------------------------------------------------------
+# Database
+# ---------------------------------------------------------------------------
+# PostgreSQL password for the paperclip-db service.
+# Generate a strong random password:
+#   openssl rand -base64 32
+PAPERCLIP_DB_PASSWORD=change_me_to_a_strong_random_password
+
+# ---------------------------------------------------------------------------
+# Authentication
+# ---------------------------------------------------------------------------
+# Secret key used by Better Auth for signing and verifying tokens.
+# Generate a strong random secret:
+#   openssl rand -base64 32
+PAPERCLIP_AUTH_SECRET=change_me_to_a_strong_random_secret