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/IntelCeleronG1101/lscpu.txt

@@ -0,0 +1,27 @@
+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
+Socket(s):           1
+NUMA node(s):        1
+Vendor ID:           GenuineIntel
+BIOS Vendor ID:      Intel
+CPU family:          6
+Model:               37
+Model name:          Intel(R) Celeron(R) CPU        G1101  @ 2.27GHz
+BIOS Model name:     Intel(R) Celeron(R) CPU        G1101  @ 2.27GHz
+Stepping:            5
+CPU MHz:             1968.782
+CPU max MHz:         2261.0000
+CPU min MHz:         1197.0000
+BogoMIPS:            4522.43
+Virtualization:      VT-x
+L1d cache:           32K
+L1i cache:           32K
+L2 cache:            256K
+L3 cache:            2048K
+NUMA node0 CPU(s):   0,1
+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 ht tm pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc cpuid aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm pcid popcnt lahf_lm pti ssbd ibrs ibpb stibp tpr_shadow vnmi flexpriority ept vpid dtherm arat flush_l1d