Fix PowerShell $Host reserved variable conflict in ROA setup scripts

- Rename $Host parameter to $DbHost in oracle-functions.ps1 (Invoke-SqlPlus,
  Test-OracleConnection, Get-OracleVersion, Test-PDB, Get-ServiceName)
- Update all function calls in 01-setup-database.ps1 to use -DbHost instead of -Host
- Fix ${Host} -> ${DbHost} in log message (line 147)
- Fix Write-Log "" -> Write-Host "" to avoid empty string parameter error
- Add DbHost/Port parameters and config.ps1 support to setup script
- Update sys-updates/README.md to clarify folder is for future patches only

Tested successfully on ROACENTRAL (10.0.20.130) with Oracle XE 21c.

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

proxmox/lxc108-oracle/roa-windows-setup/sql/sys-updates/README.md

@@ -0,0 +1,61 @@
+# SYS Updates Folder
+
+This folder is for **future patches and updates only**, not for initial setup.
+
+## Important Note
+
+The initial SYS objects (AUTH_PACK, NEWSCHEMA, EXECUTESCRIPTOS, etc.) are already
+consolidated in `../sys-objects.sql`. You do NOT need to copy the old individual
+scripts (`sys_2006_*.sql` through `sys_2026_*.sql`) here.
+
+**Initial setup order:**
+1. `sys-objects.sql` - Creates all SYS objects (tables, packages, procedures, views)
+2. Import `CONTAFIN_ORACLE.dmp` - Application schema
+3. `sys-grants.sql` - Grants and public synonyms
+4. `sys-updates/*.sql` - (Optional) Post-install patches
+
+## When to Use This Folder
+
+Place scripts here when you need to:
+- Add new grants or privileges after initial setup
+- Patch AUTH_PACK or other SYS objects
+- Add new SYS procedures/functions
+- Fix issues discovered after deployment
+
+## Naming Convention
+
+Use date-based naming for proper ordering:
+```
+YYYY_MM_DD_##_DESCRIPTION.sql
+```
+
+Examples:
+- `2026_02_15_01_AUTH_PACK_FIX.sql`
+- `2026_03_01_01_NEW_GRANT.sql`
+
+## How Scripts Are Executed
+
+1. The `run-sys-updates.sql` master script executes all `.sql` files in this folder
+2. Scripts run in alphabetical order (hence the date prefix)
+3. Each script should be idempotent (safe to run multiple times)
+
+## Template
+
+```sql
+-- ============================================================================
+-- YYYY_MM_DD_##_DESCRIPTION
+-- ============================================================================
+-- Author: Your Name
+-- Date: YYYY-MM-DD
+-- Description: What this script does
+-- ============================================================================
+
+SET SERVEROUTPUT ON
+WHENEVER SQLERROR CONTINUE
+
+-- Your SQL here
+
+-- Update version tracking (optional)
+-- EXEC CONTAFIN_ORACLE.PACK_MIGRARE.UpdateVersiune('sys_YYYY_MM_DD_##_DESCRIPTION','','SYS');
+-- COMMIT;
+```