fix(analyze): stream sessions larger than the V8 string limit

[drewstone]

Reproduction

On commit c052989, run:

pnpm exec tsx src/cli.ts analyze --harness codex --last 1 --cwd /home/drew/code/agent-dev-container-sandbox011 --out /tmp/codex-current-trace-analysis.md

Observed: exits 1 with error: Invalid string length. The selected active Codex rollout is 805,291,116 bytes. traces list can discover it, but analysis materializes enough content to exceed V8 string limits.

Required behavior

• Parse and normalize arbitrarily large JSONL sessions incrementally.
• Bound retained prompt, response, tool, span, report, and external-analysis payload bytes explicitly.
• Preserve counts, timing, failures, and truncation receipts when text is clipped.
• Add a sparse-file/generated large-session regression that proves analysis completes without allocating the full session as one string.
• Keep explicit-session and --last selection behavior identical.

This blocks analyzing long-running operator sessions with the current published/local CLI.

[drewstone]

Reproduced on a current Codex session without LLM analysis or upload.

npx --yes @tangle-network/traces@latest analyze --harness codex --last 1
pnpm --dir ~/code/traces dev analyze --harness codex --last 1 --out /tmp/report.md

Both exit 1 with error: Invalid string length; the requested output file remains empty. The published package was 0.9.4; the local checkout included c052989 fix(analysis): handle sessions above argument limits, so the existing array-spread repair is not sufficient for this session size. traces list --harness codex --last 1 succeeds, isolating the fault to analysis.