Add Takumi Guard setup step to build workflow

[KengoTODA]

No description provided.

[Copilot]

Pull request overview

Adds Takumi Guard initialization to the CI build workflow to enable npm-related protection/validation during the build pipeline.

Changes:

• Inserted flatt-security/setup-takumi-guard-npm into the Build GitHub Actions workflow.

Comments suppressed due to low confidence (1)

.github/workflows/build.yml:24

• The Takumi Guard setup step is placed before actions/setup-node, but setup-node is configured with registry-url (and typically writes npm config). If Takumi Guard also configures npm/.npmrc, running it before setup-node risks having its config overwritten, so it may not apply to npm ci/npm test. Consider moving this step to run after Set up Node.js (but before npm ci).

      - uses: flatt-security/setup-takumi-guard-npm@0f69e1fc4f2c4e55dd52abcafa7c4249cd6c7e50 # v1
      - name: Set up Node.js
        uses: actions/setup-node@395ad3262231945c25e8478fd5baf05154b1d79f # v6
        with:
          node-version: ${{ matrix.node-version }}

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[Copilot]

For traceability in workflow logs, add a name: to this step (it currently shows up as a generic "Run flatt-security/setup-takumi-guard-npm" entry).

Suggested change

	- uses: flatt-security/setup-takumi-guard-npm@0f69e1fc4f2c4e55dd52abcafa7c4249cd6c7e50 # v1
	- name: Set up Takumi Guard for npm
	uses: flatt-security/setup-takumi-guard-npm@0f69e1fc4f2c4e55dd52abcafa7c4249cd6c7e50 # v1