feat: automated weekly skill check against Claude Code changelog

Description

Add a bot-driven workflow that automatically checks this plugin's skills against the latest Claude Code changelog on a weekly cadence. When Claude Code ships changes that affect skill behavior (tool APIs, hook contracts, slash-command semantics, frontmatter conventions, MCP server contracts), the bot should surface which skills may be impacted so they can be reviewed and updated before they silently break.

Requirements

• Scheduled weekly job (e.g. GitHub Actions cron) that fetches the latest Claude Code changelog/release notes.
• Diff the changelog against the last-checked version and extract entries relevant to skills, agents, and MCP servers.
• Map changed surfaces to potentially affected skills (e.g. bloc, testing, navigation, layered-architecture, create-project).
• Output a report — open or update a tracking issue listing impacted skills and the relevant changelog entries.
• No false-quiet: if parsing fails or the changelog format changes, the job flags it rather than passing silently.

Additional Context

Pairs with the evaluation tables/data work so impacted skills can be re-tested against updates automatically. See #104.

Start at the GitHub Actions workflow entry point and review how the repository organizes skills such as bloc, testing, navigation, layered-architecture, and create-project. Trace the Claude Code changelog/release notes input and the relationship to the evaluation tables/data work in #104. Done means a weekly report identifies affected skills, tracks the last checked version, and flags parsing failures instead of passing silently.