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/IntelPentium42.80GHz/catproc.txt

@@ -0,0 +1,22 @@
+processor	: 0
+vendor_id	: GenuineIntel
+cpu family	: 15
+model		: 4
+model name	: Intel(R) Pentium(R) 4 CPU 2.80GHz
+stepping	: 1
+cpu MHz		: 2793.160
+cache size	: 1024 KB
+fdiv_bug	: no
+hlt_bug		: no
+f00f_bug	: no
+coma_bug	: no
+fpu		: yes
+fpu_exception	: yes
+cpuid level	: 3
+wp		: yes
+flags		: fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss constant_tsc up pebs bts tsc_reliable pni hypervisor
+bogomips	: 5586.32
+clflush size	: 64
+cache_alignment	: 128
+address sizes	: 40 bits physical, 32 bits virtual
+power management:

benchmark-data/data/hardware/IntelPentium42.80GHz/lscpu.txt

@@ -0,0 +1,15 @@
+Architecture:          i686
+CPU op-mode(s):        32-bit
+Byte Order:            Little Endian
+CPU(s):                2
+On-line CPU(s) list:   0,1
+Thread(s) per core:    2
+Core(s) per socket:    1
+Socket(s):             1
+Vendor ID:             GenuineIntel
+CPU family:            15
+Model:                 2
+Model name:            Intel(R) Pentium(R) 4 CPU 2.80GHz
+Stepping:              9
+CPU MHz:               2793.062
+BogoMIPS:              5586.42