Remove the Claude Code-powered duplicate PR detection workflow and revert
the duplicate issue checker back to wow-actions/potential-duplicates with
text similarity matching.
Fixes "Input must be provided either through stdin or as a prompt
argument" error by moving the prompt to a PROMPT env variable
instead of inline multiline shell string.
Route through LiteLLM proxy using LITELLM_VIRTUAL_KEY and LITELLM_BASE_URL
secrets. Also adds --repo flag to all gh commands to fix missing repo context.
Replace the text-similarity based wow-actions/potential-duplicates with
opencode CLI + Claude Sonnet for semantic duplicate detection. The LLM
reads the full issue body and searches existing issues by keywords,
error messages, providers, and components — not just title similarity.
Requires ANTHROPIC_API_KEY repo secret.
