Add persistent Oracle database setup with multiple tables

[devin-ai-integration]

Summary

This PR adds local development support for running the utPLSQL demo project with a persistent Oracle database instead of ephemeral CI/CD containers. The setup includes Docker Compose configuration with volume-based persistence and creates multiple tables demonstrating varying levels of database complexity.

Key additions:

• Docker Compose configuration with persistent volume (oracle-data) mounted to /opt/oracle/oradata
• Three tiers of table complexity: simple (lookup tables), medium (FK relationships, indexes, constraints), and complex (triggers, virtual columns, audit logging)
• Shell scripts for database setup, full installation, and persistence verification
• Comprehensive documentation in docs/PERSISTENT_DATABASE_SETUP.md

The complex tables include 5 triggers that handle automatic order total calculation, inventory tracking, customer audit logging, and timestamp updates.

Updates since last revision

Fixed SQL compatibility issues discovered during local testing:

• Added SET DEFINE OFF to all SQL scripts to prevent & character in "Home & Garden" from being interpreted as a substitution variable prompt
• Converted trg_update_order_total from a row-level trigger to a compound trigger to avoid ORA-04091 mutating table error when querying order_items during INSERT/UPDATE/DELETE
• Removed redundant indexes on columns already indexed by UNIQUE constraints (email, product_code)

Local testing confirmed: tables install successfully, triggers fire correctly, order totals are calculated, inventory transactions are logged, and data persists across container restarts.

Review & Testing Checklist for Human

• Verify compound trigger behavior - The trg_update_order_total compound trigger collects order IDs during row processing and updates totals in AFTER STATEMENT. Test with bulk inserts (e.g., INSERT INTO order_items SELECT ...) to verify totals calculate correctly for multiple rows in one statement.
• Test data persistence - Run ./scripts/verify_persistence.sh or manually stop/start the container to confirm data survives restarts
• Check inventory trigger edge cases - The trg_update_inventory is still a row-level trigger. Verify it handles product quantity updates correctly when multiple order items reference the same product in one transaction.

Recommended test plan:

1. Run ./scripts/setup_persistent_db.sh and wait for database ready
2. Run ./scripts/install_all.sh
3. Connect via sqlplus ut3_demo/ut3_demo@//127.0.0.1:1521/XE and verify tables exist
4. Query SELECT order_id, total_amount FROM orders; to verify order totals were calculated by triggers
5. Run ./scripts/verify_persistence.sh to test persistence

Notes

• Credentials are hardcoded (oracle for SYS, ut3_demo/ut3_demo for demo user) as this is a demo/development setup
• The existing CI/CD workflows are unchanged; this adds parallel local development capability
• SQL scripts were tested locally on Oracle XE 21c and work correctly on a fresh database

Link to Devin run: https://app.devin.ai/sessions/2510995b0b71448a8c395ef96d7c4fc5
Requested by: @SachetCognition

[devin-ai-integration]

Original prompt from sachet.agarwal

# Task: Set Up by_utPLSQL-demo-project with Persistent Database and Create Multiple Tables

## Background
The `SachetCognition/by_utPLSQL-demo-project` repository is a demonstration project for Oracle PL/SQL unit testing using the utPLSQL v3 testing framework with CI/CD integration. Currently, the repository uses **temporary Docker Oracle databases** (`gvenzl/oracle-xe:21-slim`) that are ephemeral and created only during CI/CD runs without persistent data.

## Objective
Modify the repository setup to:
1. Run the project locally with a persistent Oracle database (instead of temporary containers)
2. Create multiple tables with varying complexity
3. Ensure data persists across container restarts

## Current Setup Details

### Existing CI/CD Configuration
The repository has two CI/CD approaches:
- **GitHub Actions**: Located in `.github/workflows/build.yml` - uses Docker service containers with `gvenzl/oracle-xe:21-slim` image
- **Azure DevOps**: Uses templates in `.azure_templates/t-task-extend-create-docker-database.yml` that create temporary Oracle containers

### Required Dependencies
Before starting, ensure you have installed:
- Docker (for Oracle database containers)
- SQLcl (Oracle SQL command line tool)
- utPLSQL-cli (command line interface for testing)
- Oracle Database Docker image: `gvenzl/oracle-xe:21-slim`

## Tasks to Complete

### 1. Set Up Persistent Oracle Database
- Create a Docker Compose configuration or Docker run command that:
  - Uses the `gvenzl/oracle-xe:21-slim` image
  - Mounts a volume for data persistence (so data survives container restarts)
  - Exposes the Oracle database port (typically 1521)
  - Sets up appropriate environment variables for database credentials

### 2. Install utPLSQL Framework
- Install the utPLSQL v3 testing framework into the persistent database
- Reference the existing CI/CD workflows to understand the installation process

### 3. Create Multiple Tables with Varying Complexity
Create at least 3-5 tables with differen... (1419 chars truncated...)

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