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/IntelU7300/catproc.txt

@@ -0,0 +1,25 @@
+processor	: 0
+vendor_id	: GenuineIntel
+cpu family	: 6
+model		: 23
+model name	: Genuine Intel(R) CPU           U7300  @ 1.30GHz
+stepping	: 10
+microcode	: 0xa07
+cpu MHz		: 1300.000
+cache size	: 3072 KB
+physical id	: 0
+siblings	: 2
+core id		: 0
+cpu cores	: 2
+apicid		: 0
+initial apicid	: 0
+fpu		: yes
+fpu_exception	: yes
+cpuid level	: 13
+wp		: yes
+flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good nopl aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm sse4_1 xsave lahf_lm dts tpr_shadow vnmi flexpriority
+bogomips	: 3466.59
+clflush size	: 64
+cache_alignment	: 64
+address sizes	: 36 bits physical, 48 bits virtual
+power management:

benchmark-data/data/hardware/IntelU7300/lscpu.txt

@@ -0,0 +1,18 @@
+Architecture:          x86_64
+CPU op-mode(s):        32-bit, 64-bit
+Byte Order:            Little Endian
+CPU(s):                2
+On-line CPU(s) list:   0,1
+Thread(s) per core:    1
+Core(s) per socket:    2
+CPU socket(s):         1
+Vendor ID:             GenuineIntel
+CPU family:            6
+Model:                 23
+Stepping:              10
+CPU MHz:               1300.000
+BogoMIPS:              3466.59
+Virtualization:        VT-x
+L1d cache:             32K
+L1i cache:             32K
+L2 cache:              3072K