feat(skills): Add triage and digest workflow skills; enrich fix-issues - #179

The autonomous triage skill loads attacker-controllable Sentry issue titles, culprits, and messages into LLM context while granting the Bash tool that no part of its documented workflow uses; a prompt-injection payload embedded in issue content could leverage Bash to run arbitrary shell commands, especially in unattended --auto mode. Drop Bash from allowed-tools since the workflow only needs the MCP issue tools plus Read/Grep/Glob.