feat(cli): add Jev session compaction

[codeaholicguy]

Summary

• add ai-devkit agent session compact --id <session-id> [--type <provider>] [--format markdown|json]
• require TYPESAFE_API_KEY before session discovery or transcript reads, returning an explicit Jev-unavailable result when absent with no fallback
• classify redacted session events through the TypeSafe Jev SDK and build deterministic Markdown or JSON continuation artifacts
• add network-free service, SDK-boundary, CLI, and built-in skill coverage plus lifecycle documentation

Validation

• npm run lint
• npm run build
• npm test (all six projects; CLI 98 files / 1176 tests)

Risks

• classification is intentionally sequential and makes one Jev request per source message, so very long sessions may have noticeable latency and API cost
• no live paid-key call was run; the SDK boundary is covered with deterministic mocks