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/2xIntelXeonE5-2683v4/catproc.txt

@@ -0,0 +1,25 @@
+processor	: 0
+vendor_id	: GenuineIntel
+cpu family	: 6
+model		: 79
+model name	: Intel(R) Xeon(R) CPU E5-2683 v4 @ 2.10GHz
+stepping	: 1
+microcode	: 184549392
+cpu MHz		: 1200.000
+cache size	: 40960 KB
+physical id	: 0
+siblings	: 32
+core id		: 0
+cpu cores	: 16
+apicid		: 0
+initial apicid	: 0
+fpu		: yes
+fpu_exception	: yes
+cpuid level	: 20
+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 pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts rep_good xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 fma cx16 xtpr pdcm pcid dca sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm abm 3dnowprefetch ida arat epb xsaveopt pln pts dtherm invpcid_single pti retpoline tpr_shadow vnmi flexpriority ept vpid fsgsbase bmi1 hle avx2 smep bmi2 erms invpcid rtm cqm rdseed adx cqm_llc cqm_occup_llc
+bogomips	: 4190.45
+clflush size	: 64
+cache_alignment	: 64
+address sizes	: 46 bits physical, 48 bits virtual
+power management: