Add Kiro CLI as third coding agent with hooks and CLI skill

[b0x42]

Adds Kiro CLI as a third coding agent alongside Claude Code and Codex in Settings → Coding Agents.

Changes

New files

• KiroHookSettings.swift — Hook entry struct (command + timeout_ms) and payloads for progress (userPromptSubmit → busy on, stop → busy off) and notification (stop → notify) events
• KiroHookSettingsFileInstaller.swift — File installer for Kiro's flat hook format: install, uninstall, and containsMatchingHooks
• KiroSettingsInstaller.swift — Targets ~/.kiro/agents/kiro_default.json, creates default agent config when file is absent
• KiroSettingsClient.swift — TCA dependency client wrapping the installer

Modified files

• AgentHooksInstallState.swift — Added .kiroProgress, .kiroNotifications to AgentHookSlot
• SkillAgent.swift — Added .kiro case with configDirectoryName: ".kiro"
• SettingsFeature.swift — Wired Kiro state, dependency, check/install/uninstall effects
• DeveloperSettingsView.swift — Added Kiro section with progress, notifications, and CLI skill rows
• CLISkillContent.swift — Added kiroSkillMd (SKILL.md with YAML frontmatter)
• CLISkillInstaller.swift — Added .kiro case
• AgentHookSocketServer.swift — Added assistant_response decoding (see below)

Assets

• kiro-mark image set (SVG from kiro.dev)

Design decisions

Why kiro_default.json

Kiro has no global hooks file — hooks live per-agent in ~/.kiro/agents/<name>.json. The kiro_default agent is what runs in Supacode terminals, so that's the only file we target. The built-in kiro_default has no file on disk; creating kiro_default.json overrides it entirely, so the installer writes a complete config (name, tools, resources, hooks) — not just hooks.

Why a separate KiroHookSettingsFileInstaller

Kiro's hook format is flat:

{ "hooks": { "stop": [{ "command": "...", "timeout_ms": 10000 }] } }

Claude/Codex use a grouped format:

{ "hooks": { "Stop": [{ "hooks": [{ "type": "command", "command": "...", "timeout": 10 }] }] } }

Rather than generalizing AgentHookSettingsFileInstaller and risking regressions in Claude/Codex, this isolates the format difference in a separate installer.

Socket server: assistant_response field

Kiro sends the agent's final response in assistant_response rather than message (Claude) or last_assistant_message (Codex). Extended the notification body fallback chain:

let body = payload.message ?? payload.lastAssistantMessage ?? payload.assistantResponse

Without this, Kiro notifications would have empty bodies.

Uninstall safety

Uninstall is a no-op if kiro_default.json doesn't exist, preventing creation of a broken config file that would override Kiro's built-in agent with missing fields.

Verification

• make check passes (swift-format + swiftlint)
• make test passes (716 tests, 57 suites)

[sbertix]

Thanks 💪 just a few changes required, though.