Add interactive skill report card CLI

[prithvi2206]

Problem or Objective

• Launch a pre-auth, local CLI surface for Agent Instruction Governance.
• Let users find and score local agent instruction files without wiring a Promptless backend flow first.

Solution

• Add promptless skill-report-card with interactive discovery, checkbox selection, optional LLM review through detected claude/codex CLIs, deterministic scoring, and HTML report generation.
• Wire the command into registry, top-level help, shell completions, README docs, and package metadata.
• Add tests for discovery, scoring, report rendering, token estimates, and skill-validator JSON parsing.

Design Choices

• Keep the default UX interactive, while supporting --yes, --llm, --out, and --fail-under for scripted runs.
• Treat skill-validator as an internal best-effort component, not a user-facing prompt; cap validator subprocesses on large scans.
• Keep deterministic checks local by default and only send file contents to an LLM when the user explicitly opts in.

Validation

• npm run typecheck
• npm test
• npm run build
• node dist/cli.js skill-report-card /Users/prithvi/.codex/worktrees/b4c2/promptless --yes --llm off --no-machine-scan --no-open --max-directories 5000 --out /tmp/promptless-skill-report-card-smoke.html