feat: 대역폭 추정 및 DAU 표시 기능 추가

- 동시접속자 기반 월간 대역폭 자동 추정
- DAU(일일활성사용자) 추정치 표시 (동접 × 10-14)
- 대역폭 기반 Linode/Vultr 자동 선택 로직
- 비용 분석에 대역폭 비용 포함
- 지역 미선택시 서울/도쿄/오사카/싱가포르 기본 표시
- 지역별 서버 분리 표시 (GROUP BY instance + region)

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

benchmark-data/data/hardware/2xIntelXeonX5675/catproc.txt

@@ -0,0 +1,24 @@
+processor	: 0
+vendor_id	: GenuineIntel
+cpu family	: 6
+model		: 44
+model name	: Intel(R) Xeon(R) CPU           X5675  @ 3.07GHz
+stepping	: 2
+cpu MHz		: 1600.000
+cache size	: 12288 KB
+physical id	: 1
+siblings	: 12
+core id		: 0
+cpu cores	: 6
+apicid		: 32
+initial apicid	: 32
+fpu		: yes
+fpu_exception	: yes
+cpuid level	: 11
+wp		: yes
+flags		: fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts rep_good xtopology nonstop_tsc aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 sse4_2 popcnt aes lahf_lm ida arat epb dts tpr_shadow vnmi flexpriority ept vpid
+bogomips	: 6133.62
+clflush size	: 64
+cache_alignment	: 64
+address sizes	: 40 bits physical, 48 bits virtual
+power management:

benchmark-data/data/hardware/2xIntelXeonX5675/lscpu.txt

@@ -0,0 +1,22 @@
+Architecture:          x86_64
+CPU op-mode(s):        32-bit, 64-bit
+Byte Order:            Little Endian
+CPU(s):                24
+On-line CPU(s) list:   0-23
+Thread(s) per core:    2
+Core(s) per socket:    6
+CPU socket(s):         2
+NUMA node(s):          2
+Vendor ID:             GenuineIntel
+CPU family:            6
+Model:                 44
+Stepping:              2
+CPU MHz:               1600.000
+BogoMIPS:              6133.25
+Virtualization:        VT-x
+L1d cache:             32K
+L1i cache:             32K
+L2 cache:              256K
+L3 cache:              12288K
+NUMA node0 CPU(s):     1,3,5,7,9,11,13,15,17,19,21,23
+NUMA node1 CPU(s):     0,2,4,6,8,10,12,14,16,18,20,22