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/IntelPentiumE5500/catproc.txt

@@ -0,0 +1,28 @@
+processor	: 0
+vendor_id	: GenuineIntel
+cpu family	: 6
+model		: 23
+model name	: Pentium(R) Dual-Core  CPU      E5500  @ 2.80GHz
+stepping	: 10
+microcode	: 0xa07
+cpu MHz		: 1203.000
+cache size	: 2048 KB
+physical id	: 0
+siblings	: 2
+core id		: 0
+cpu cores	: 2
+apicid		: 0
+initial apicid	: 0
+fdiv_bug	: no
+f00f_bug	: no
+coma_bug	: no
+fpu		: yes
+fpu_exception	: yes
+cpuid level	: 13
+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 nx lm constant_tsc arch_perfmon pebs bts aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm xsave lahf_lm dtherm tpr_shadow vnmi flexpriority
+bogomips	: 5586.37
+clflush size	: 64
+cache_alignment	: 64
+address sizes	: 36 bits physical, 48 bits virtual
+power management:

benchmark-data/data/hardware/IntelPentiumE5500/lscpu.txt

@@ -0,0 +1,16 @@
+Architecture:          x86_64
+CPU op-mode(s):        32-bit, 64-bit
+CPU(s):                2
+Thread(s) per core:    1
+Core(s) per socket:    2
+CPU socket(s):         1
+NUMA node(s):          1
+Vendor ID:             GenuineIntel
+CPU family:            6
+Model:                 23
+Stepping:              10
+CPU MHz:               2801.106
+Virtualization:        VT-x
+L1d cache:             32K
+L1i cache:             32K
+L2 cache:              2048K