Add ROA Oracle Database Windows setup scripts with old client support

PowerShell scripts for setting up Oracle 21c/XE with ROA application:
- Automated tablespace, user creation and imports
- sqlnet.ora config for Instant Client 11g/ODBC compatibility
- Oracle 21c read-only Home path handling (homes/OraDB21Home1)
- Listener restart + 10G password verifier for legacy auth
- Tested on VM 302 with CONTAFIN_ORACLE schema import

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,11 @@
+# Claude Code handoff files
+.claude/HANDOFF.md
+
+# Input/backup files (large DMP files)
+input/
+
+# IDE files
+.idea/
+.vscode/
+*.swp
+*.swo