fix(claude): discover macOS Claude-3p Cowork sessions

[akapti]

Summary

Claude Desktop Cowork on current macOS 3p builds stores usage under ~/Library/Application Support/Claude-3p/local-agent-mode-sessions/. The path override only selects a directory; it does not make CodeBurn understand the Cowork usage-ledger format.

Findings

• Normal Claude Code usage is parsed from .claude/projects/**/*.jsonl by the existing Claude transcript parser in src/parser.ts.
• The Claude-3p data contains usage-ledger/*.ndjson files with surface, models, token counts, and nested models.*.cost.usd values.
• Before this change, CodeBurn did not discover those ledger files or parse their cost fields, so setting CODEBURN_DESKTOP_SESSIONS_DIR alone produced no Cowork usage records.
• The ledger schema is different from the normal Claude transcript schema, so the existing parseApiCall() function cannot be reused directly without misreading the records.

Changes

• Discover both the classic macOS Claude Desktop root and the Claude-3p root.
• Discover Cowork usage-ledger/*.ndjson files beneath either root.
• Add a focused Cowork ledger adapter in src/providers/claude.ts that reuses the existing streaming line reader, date filtering, token accounting, cost calculation fallback, parsed-call model, cache, aggregation, and reporting pipeline.
• Use the recorded cost.usd when present and estimate cost with the existing Claude pricing helper when it is absent.
• Preserve the existing normal Claude JSONL parser unchanged for regular Claude Code sessions.
• Add regression and end-to-end tests for discovery, parsing, cost, token fields, surface filtering, and aggregation.
• Bump the Claude parse version so existing caches are reparsed with ledger support.

Verification

• Real Claude-3p data from ~/Library/Application Support/Claude-3p/local-agent-mode-sessions: 5 Cowork ledger records, 2 sessions, and $1.0454102 recorded cost were parsed successfully. The built CLI reported Claude Cowork: Cost (USD) 1.05, API Calls 5, Sessions 2.
• Claude provider doctor: 7 candidates found, 7 parsed successfully, 0 failures.
• Focused tests: 51 passed across the Claude provider and parser suites.
• npx tsc --noEmit passed.
• npm run build:cli passed.
• Full test suite: 345 files passed, 5 failed due to the environment Git rejecting git init -b main; 4,666 tests passed, 13 failed for the same unrelated issue.