fix(ci): run release workflows on Node 24 actions

[mrgoonie]

Summary

• Upgrade CI and release workflows from actions/checkout@v4 to actions/checkout@v6.
• Upgrade CI and release workflows from actions/setup-go@v5 to actions/setup-go@v6.
• Opt the release workflow into Node 24 action execution for go-semantic-release/action@v1, whose latest v1 metadata still declares Node 20.
• Update the deployment guide workflow snippets to match the live CI/release workflows.

Validation

• YAML parse for all workflow files
• /usr/local/go/bin/go test -count=1 ./...
• /usr/local/go/bin/go vet ./...
• /usr/local/go/bin/go build ./...
• git diff --check

Notes

• actions/checkout@v6.0.2 and actions/setup-go@v6.4.0 declare Node 24 upstream.
• go-semantic-release/action@v1.24.1 still declares Node 20, so the workflow-level FORCE_JAVASCRIPT_ACTIONS_TO_NODE24=true opt-in is required until upstream publishes a Node 24 action runtime.
• Claude workflow files are intentionally unchanged here because Anthropic app-token validation rejects PR runs when the review workflow content differs from the default branch.