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/AMDAthlon5350APU/lscpu.txt

@@ -0,0 +1,24 @@
+Architecture:          x86_64
+CPU op-mode(s):        32-bit, 64-bit
+Byte Order:            Little Endian
+CPU(s):                4
+On-line CPU(s) list:   0-3
+Thread(s) per core:    1
+Core(s) per socket:    4
+Socket(s):             1
+NUMA node(s):          1
+Vendor ID:             AuthenticAMD
+CPU family:            22
+Model:                 0
+Model name:            AMD Athlon(tm) 5350 APU with Radeon(tm) R3
+Stepping:              1
+CPU MHz:               800.000
+CPU max MHz:           2050,0000
+CPU min MHz:           800,0000
+BogoMIPS:              4092.35
+Virtualization:        AMD-V
+L1d cache:             32K
+L1i cache:             32K
+L2 cache:              2048K
+NUMA node0 CPU(s):     0-3
+Flags:                 fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb rdtscp lm constant_tsc rep_good nopl nonstop_tsc extd_apicid aperfmperf pni pclmulqdq monitor ssse3 cx16 sse4_1 sse4_2 movbe popcnt aes xsave avx f16c lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs skinit wdt topoext perfctr_nb bpext perfctr_l2 hw_pstate proc_feedback ssbd vmmcall bmi1 xsaveopt arat npt lbrv svm_lock nrip_save tsc_scale flushbyasid decodeassists pausefilter pfthreshold overflow_recov