Implement unified Oracle mode support with auto-detection

- Unified Dockerfile with thick/thin mode auto-detection
- Single docker-compose.yaml with build arguments
- Auto-detect logic: thick mode for Oracle 10g/11g, thin mode for 12.1+
- Simplified .env configuration with clear mode selection
- Updated admin.py with FORCE_THIN_MODE and INSTANTCLIENTPATH support
- Added comprehensive documentation for both deployment modes
- Container tested successfully with thick mode for Oracle 11g compatibility

🤖 Generated with [Claude Code](https://claude.ai/code)

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

api/Dockerfile

@@ -1,33 +1,38 @@
-# Multi-stage build for Oracle Instant Client + Python Flask
-FROM python:3.11.4-slim-buster as oracle_base
+# UNIFIED Dockerfile - AUTO-DETECT Thick/Thin Mode
+FROM python:3.11-slim as base
 
-# Installing Oracle instant client
-WORKDIR /opt/oracle
-RUN apt-get update && apt-get install -y libaio1 wget unzip curl \
-    && wget https://download.oracle.com/otn_software/linux/instantclient/instantclient-basiclite-linuxx64.zip \
-    && unzip instantclient-basiclite-linuxx64.zip \
-    && rm -f instantclient-basiclite-linuxx64.zip \
-    && cd /opt/oracle/instantclient* \
-    && rm -f *jdbc* *occi* *mysql* *README *jar uidrvci genezi adrci \
-    && echo /opt/oracle/instantclient* > /etc/ld.so.conf.d/oracle-instantclient.conf \
-    && ldconfig
+# Set argument for build mode (thick by default for compatibility)
+ARG ORACLE_MODE=thick
 
-# Application layer
-FROM oracle_base
+# Base application setup
 WORKDIR /app
-
-# Copy TNS configuration for Oracle connection
-COPY tnsnames.ora /app/tnsnames.ora
 COPY requirements.txt /app/requirements.txt
-
-# Install Python dependencies
 RUN pip3 install -r requirements.txt
 
-# Copy application code
+# Oracle Instant Client installation (only if thick mode)
+RUN if [ "$ORACLE_MODE" = "thick" ] ; then \
+    apt-get update && apt-get install -y libaio-dev wget unzip curl && \
+    mkdir -p /opt/oracle && cd /opt/oracle && \
+    wget https://download.oracle.com/otn_software/linux/instantclient/instantclient-basiclite-linuxx64.zip && \
+    unzip instantclient-basiclite-linuxx64.zip && \
+    rm -f instantclient-basiclite-linuxx64.zip && \
+    cd /opt/oracle/instantclient* && \
+    rm -f *jdbc* *occi* *mysql* *README *jar uidrvci genezi adrci && \
+    echo /opt/oracle/instantclient* > /etc/ld.so.conf.d/oracle-instantclient.conf && \
+    ldconfig && \
+    ln -sf /usr/lib/x86_64-linux-gnu/libaio.so.1t64 /usr/lib/x86_64-linux-gnu/libaio.so.1 ; \
+    else \
+    echo "Thin mode - skipping Oracle Instant Client installation" ; \
+    fi
+
+# Copy application files
 COPY . .
 
-# Health check endpoint
+# Create logs directory
+RUN mkdir -p /app/logs
+
+# Expose port
 EXPOSE 5000
 
-# Run Flask application
+# Run Flask application with auto-detect mode
 CMD ["gunicorn", "--bind", "0.0.0.0:5000", "admin:app", "--reload", "--access-logfile", "-"]