✨ feat(confession): split ci checks and harden cli scanning

[BlackishGreen33]

變更摘要\n- 將 CI 拆分為 lint/build/test 並行 job，保留 quality 聚合 gate 與 commit-check\n- 新增 check:lint/check:build/check:test，並讓 check:ci 串接三者\n- 強化 confession CLI：參數驗證、scan 逾時與 SIGINT 主動 cancel、可測試入口\n- 新增 CLI node:test 覆蓋 init/list/status/scan 成功失敗與 cancel 路徑\n- 同步更新 steering、AGENTS、README、CLI README\n\n## 驗證\n- pnpm lint\n- pnpm test\n- pnpm build\n- pnpm check:ci

[Copilot]

Pull request overview

This PR restructures CI into parallelized lint/build/test jobs with a preserved quality aggregate gate, and hardens the confession-cli scan flow with stricter flag validation plus proactive cancellation on timeout/SIGINT, backed by new Node node:test coverage.

Changes:

• Split CI into lint / build / test jobs and add a quality aggregator gate while keeping commit-check.
• Add root scripts check:lint, check:build, check:test, and make check:ci chain them.
• Refactor confession-cli to support testable runtime injection, strict flag/enum validation, scan timeout, and SIGINT-triggered cancel; add CLI tests.

Reviewed changes

Copilot reviewed 9 out of 11 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
package.json	Adds check:* scripts and includes CLI tests in pnpm test.
confession-cli/package.json	Adds node --test test script for the CLI package.
confession-cli/bin/confession.test.js	New Node node:test suite covering init/list/status/scan success/failure/timeout/SIGINT.
confession-cli/bin/confession.js	Adds runtime injection + validation + scan cancel-on-timeout/SIGINT and refactors CLI entry to return exit codes.
confession-cli/README.md	Documents stricter validation and scan cancellation behavior.
README.md	Updates repo structure, testing matrix, CI commands, and CLI behavior notes.
AGENTS.md	Updates repo map and testing/CI guidance to include CLI + split CI jobs.
.kiro/steering/testing-standards.md	Updates testing standards to include CLI node:test and coverage expectations.
.kiro/steering/tech.md	Updates tech matrix and lists new CI sub-check commands.
.kiro/steering/structure.md	Updates structure docs for split CI and CLI test file location.
.github/workflows/ci.yml	Implements parallel lint/build/test jobs plus quality gate and workflow concurrency cancellation.

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