feat(adapter): add Kiro CLI export adapter

[VedantMadane]

Closes #46

Adds an export adapter for AWS Kiro CLI custom agents.

What it does

Generates two outputs from a gitagent directory:

1. Agent config JSON (.kiro/agents/<name>.json) with:

   • name, description, model from the manifest
   • prompt as a file://./prompt.md URI (Kiro's recommended pattern for long prompts)
   • tools and allowedTools collected from skills frontmatter and tools/*.yaml
   • mcpServers from tool YAML files that declare mcp_server
   • hooks mapped to Kiro's event model (PreToolUse, PostToolUse, Notification, Stop)

2. Prompt markdown (prompt.md) built from SOUL.md, RULES.md, DUTIES.md, skills, tools, knowledge, and compliance sections -- same pattern as the Gemini and Codex adapters.

Files changed

• src/adapters/kiro.ts -- new adapter (306 lines)
• src/adapters/index.ts -- add kiro export
• src/commands/export.ts -- add kiro format to switch and help text

Usage

gitagent export -f kiro -d ./my-agent

Reference

Based on Kiro CLI configuration reference and follows the same adapter pattern as gemini.ts and codex.ts.

[shreyas-lyzr]

Reviewed and merged with fixes.

What was correct:

• Config structure matches Kiro docs: .kiro/agents/<name>.json with name, description, prompt, model, tools, allowedTools, mcpServers, hooks, welcomeMessage
• file://./prompt.md URI syntax for prompts is correct
• MCP server collection from tools/*.yaml is a nice addition
• Uses shared buildComplianceSection (no duplication)
• Follows existing adapter patterns

Fixes applied:

1. Hook event names were PascalCase — Kiro uses camelCase. Changed PreToolUse → preToolUse, PostToolUse → postToolUse, Stop → stop. Added agentSpawn and userPromptSubmit mappings.
2. Notification hook event doesn't exist in Kiro. Removed — Kiro only supports 5 events: agentSpawn, userPromptSubmit, preToolUse, postToolUse, stop.
3. TypeScript error — mcp.name could be undefined, added non-null assertion since it's inside a if (mcp_server?.name) guard.

Verified against Kiro CLI configuration reference. Thanks @VedantMadane!

[VedantMadane]

Closing — the Kiro adapter is already in main. Thanks for the review!