Dashboard: Add Physical Memory, SQL Server Memory, Target Memory summary cards to Memory Overview

[erikdarlingdata]

Problem

Lite's Memory > Overview tab shows 6 at-a-glance summary cards above the chart:

• Physical Memory (total server RAM, e.g. 64.0 GB)
• SQL Server Memory (committed, e.g. 27.3 GB)
• Target Memory (what SQL Server wants, e.g. 56.0 GB)
• Buffer Pool (e.g. 21.4 GB)
• Plan Cache (e.g. 5.2 GB)
• System Memory State (e.g. "Available physical memory is high")

Dashboard's Memory Overview footer only shows: Buffer Pool %, Plan Cache %, Utilization %, Pressure status. It's missing the absolute GB values and specifically missing Physical Memory, SQL Server Memory (committed), and Target Memory.

Data availability

• collect.memory_stats has: buffer_pool_mb, plan_cache_mb, total_memory_mb (clerk total), physical_memory_in_use_mb, available_physical_memory_mb, memory_utilization_percentage
• Missing from memory_stats: total_physical_memory_mb (server RAM) and target_memory_mb (SQL committed target)
• collect.cpu_scheduler_stats has total_physical_memory_kb — could be joined or the column could be added to memory_stats
• collect.memory_grant_stats has target_memory_mb — same approach
• sys.dm_os_sys_info has committed_target_kb (target memory)
• sys.dm_os_sys_memory has total_physical_memory_kb (server RAM)
• sys.dm_os_process_memory has committed_kb (SQL Server committed memory)

Proposed fix

1. Add total_physical_memory_mb and committed_target_memory_mb columns to collect.memory_stats table
2. Update collect.memory_stats_collector to pull from sys.dm_os_sys_memory and sys.dm_os_sys_info
3. Add properties to MemoryStatsItem model
4. Update Dashboard memory overview footer to match Lite's card layout with absolute GB values