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/8xIntelXeonE5620/catproc.txt

@@ -0,0 +1,22 @@
+processor	: 0
+vendor_id	: GenuineIntel
+cpu family	: 6
+model		: 44
+model name	: Intel(R) Xeon(R) CPU           E5620  @ 2.40GHz
+stepping	: 2
+cpu MHz		: 1600.000
+cache size	: 12288 KB
+physical id	: 0
+siblings	: 1
+core id		: 0
+cpu cores	: 1
+fpu		: yes
+fpu_exception	: yes
+cpuid level	: 11
+wp		: yes
+flags		: fpu tsc msr pae cx8 apic mtrr cmov pat clflush acpi mmx fxsr sse sse2 ss ht syscall lm constant_tsc ida arat pni vmx est ssse3 cx16 sse4_1 sse4_2 popcnt lahf_lm
+bogomips	: 6027.13
+clflush size	: 64
+cache_alignment	: 64
+address sizes	: 40 bits physical, 48 bits virtual
+power management:

benchmark-data/data/hardware/8xIntelXeonE5620/lscpu.txt

@@ -0,0 +1,17 @@
+Architecture:          x86_64
+CPU op-mode(s):        64-bit
+CPU(s):                8
+Thread(s) per core:    1
+Core(s) per socket:    1
+CPU socket(s):         8
+Vendor ID:             GenuineIntel
+CPU family:            6
+Model:                 44
+Stepping:              2
+CPU MHz:               2400.154
+Hypervisor vendor:     Xen
+Virtualization type:   para
+L1d cache:             32K
+L1i cache:             32K
+L2 cache:              256K
+L3 cache:              12288K