feat(kiro): add Kiro CLI session discovery and parsing

[inola-ww]

Summary

The Kiro provider currently only detects sessions from the Kiro IDE (VS Code-based) stored in globalStorage/kiro.kiroagent. This adds support for Kiro CLI (kiro-cli chat) sessions stored in ~/.kiro/sessions/cli/.

Problem

Users running kiro-cli chat have their sessions stored in a different location (~/.kiro/sessions/cli/*.jsonl) with a different format than the IDE. Codeburn currently cannot detect these sessions.

Changes

• CLI session discovery: scans ~/.kiro/sessions/cli/ for .jsonl files, reads project name from companion .json metadata
• CLI JSONL parser: extracts per-turn data (user messages, assistant output, tool usage) from the Prompt/AssistantMessage/ToolResults entry format
• Cost from metering: uses metering_usage credits from the session metadata (actual cost, not estimated)
• CLI tool name mappings: adds read, write, shell, grep, glob to toolNameMap
• KIRO_HOME env var: respects the override for users who relocated their .kiro directory
• Testability: third optional param cliSessionsDirOverride on createKiroProvider (defaults to non-scanning when IDE dir is overridden, so existing tests are unaffected)

CLI session format

~/.kiro/sessions/cli/
├── <session-uuid>.jsonl    # conversation transcript (NDJSON: Prompt, AssistantMessage, ToolResults, Clear)
├── <session-uuid>.json     # session metadata (session_id, cwd, model_info, user_turn_metadatas with metering)
├── <session-uuid>.history  # input history
└── <session-uuid>.lock     # session lock

Testing

• All 32 existing Kiro tests pass unchanged
• 4 new unit tests covering CLI discovery and parsing
• Verified against real Kiro CLI sessions on Linux
• Cross-platform safe: Kiro CLI uses $HOME/.kiro/ on all platforms (confirmed from binary), and path.join(homedir(), '.kiro', ...) resolves correctly everywhere