PR #366 routes Reddit URLs found in web-search results through the public
Reddit JSON API to recover thread body + top comments (the Claude Code
WebFetch tool blocks reddit.com directly). That bypass is sound and the
fixed problem is real - but the always-on shape ignores user intent on
source gating.
A user who sets EXCLUDE_SOURCES=reddit to suppress Reddit results would
still get Reddit content smuggled back in via web-search URLs that
happen to point at reddit.com threads. This contradicts the suppression
contract that EXCLUDE_SOURCES is supposed to provide (see
lib/pipeline.available_sources where the same env var gates the
top-level Reddit source).
Add a _reddit_excluded(config) check in web_search() that mirrors the
parsing pattern from lib/pipeline (comma-separated, case-insensitive,
whitespace-tolerant). When reddit is in EXCLUDE_SOURCES, skip the
enrichment pass entirely - the web results themselves still flow
through, but they're not augmented with Reddit body/comments.
Four new tests in test_grounding_v3.py cover:
- EXCLUDE_SOURCES=reddit skips enrichment
- case-insensitive parsing matches REDDIT/Reddit/whitespace-padded/csv
- Other sources in EXCLUDE_SOURCES don't trigger the gate
- Enrichment runs normally when reddit isn't excluded
19/19 grounding tests pass.