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/IntelCore2DuoT7500/catproc.txt

@@ -0,0 +1,18 @@
+processor	: 0
+vendor_id	: GenuineIntel
+cpu family	: 6
+model		: 15
+model name	: Intel(R) Core(TM)2 Duo CPU     T7500  @ 2.20GHz
+stepping	: 10
+cpu MHz		: 2194.596
+cache size	: 4096 KB
+fpu		: yes
+fpu_exception	: yes
+cpuid level	: 10
+wp		: yes
+flags		: fpu de tsc msr pae cx8 cmov pat clflush mmx fxsr sse sse2 ss ht syscall lm rep_good aperfmperf unfair_spinlock pni ssse3 cx16 hypervisor lahf_lm ida dts
+bogomips	: 4389.19
+clflush size	: 64
+cache_alignment	: 64
+address sizes	: 36 bits physical, 48 bits virtual
+power management:

benchmark-data/data/hardware/IntelCore2DuoT7500/lscpu.txt

@@ -0,0 +1,21 @@
+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:    1
+CPU socket(s):         2
+NUMA node(s):          1
+Vendor ID:             GenuineIntel
+CPU family:            6
+Model:                 15
+Stepping:              10
+CPU MHz:               2194.596
+BogoMIPS:              4389.19
+Hypervisor vendor:     Xen
+Virtualization type:   para
+L1d cache:             32K
+L1i cache:             32K
+L2 cache:              4096K
+NUMA node0 CPU(s):     0,1