Add show-metrics command (Issue #353)

[Sid-V5]

added a show-metrics command (alias metrics) to fetch and display Apps Script project metrics, addressing issue #353.

Changes

• src/core/project.ts: Added getMetrics() method to the Project class, creating a wrapper around script.projects.getMetrics.
• src/commands/show-metrics.ts: Implemented the new command. It displays 'Active Users', 'Failed Executions', and 'Total Executions' with valid start/end times. Supports --json flag.
• src/commands/program.ts: Registered the show-metrics command.

Usage

clasp show-metrics
# OR
clasp metrics
# OR
clasp metrics --json

This feature provides a quick way to check project health directly from the CLI.

Resolves #353

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