Fix Claude 1-hour cache write pricing

[ozymandiashh]

Summary

• parse Claude Code's usage.cache_creation.ephemeral_5m_input_tokens and usage.cache_creation.ephemeral_1h_input_tokens split when present
• price 5-minute cache writes at the existing LiteLLM cache-write rate and 1-hour cache writes at 1.6x that rate, matching Anthropic's 2x base input pricing for 1-hour cache writes
• preserve legacy behavior when only cache_creation_input_tokens exists, so older Claude JSONL still prices all cache writes at the 5-minute rate
• keep report/export cache-write token totals as the aggregate write count while only changing cost math
• bump the daily cache to v6 so historical cached rollups with under-reported Claude costs are discarded and recomputed from raw sessions
• document the Claude pricing split and add changelog coverage plus focused regression tests

Closes #276.

Validation

• npm run build
• npx vitest run tests/parser-claude-cwd.test.ts tests/models.test.ts tests/models-hoist.test.ts tests/daily-cache.test.ts (4 files / 103 tests)
• npx vitest run (47 files / 665 tests)
• git diff --check
• Argus local reviewer: PASS
• Claude Opus 4.7 effort max: PASS
• Gemini 3.1 Pro Preview: PASS

Notes

• Anthropic's pricing docs list 5-minute cache writes at 1.25x base input and 1-hour cache writes at 2x base input, so 2.0 / 1.25 = 1.6 over the existing LiteLLM cache_creation_input_token_cost field: https://platform.claude.com/docs/en/about-claude/pricing

[AgentSeal]

Superseded by #317 which includes conflict resolution and cleaned-up changelog entries.