## Problem
CLI-created community corpus items (tier 3) were stored correctly but
invisible via API queries. Two issues blocked discoverability:
1. **Prefix mismatch**: API hardcoded 'community://pattern/' for
aggregated patterns, but CLI creates 'community://rust/http/...' URIs
2. **Query parameter parsing**: Axum's default parser doesn't support
bracket notation (?sources[]=value) used by the dashboard
Result: 0/22 CLI-created items were queryable.
## Solution
### Fix 1: Broaden Community Prefix
- Changed: 'community://pattern/' → 'community://' in corpus handler
- Impact: Now matches both aggregated patterns AND CLI-created items
- Backward compatible: Broader prefix includes narrower results
### Fix 2: Add QsQuery Extractor
- Added: serde_qs dependency + custom QsQuery extractor
- Supports: Bracket notation for array parameters (?sources[]=a&sources[]=b)
- Compatible: Works with JavaScript URLSearchParams standard
- Tested: 3 new unit tests for extractor behavior
## Verification
- ✅ All 22 CLI-created community items now queryable (was 0)
- ✅ Source filtering works: community (22), RFC (2), vendor (5)
- ✅ Multi-source queries work: ?sources[]=community&sources[]=rfc → 24
- ✅ All 89 API tests pass + 3 new extractor tests
- ✅ Clippy clean (0 warnings)
- ✅ No regressions in existing functionality
## Files Changed
- crates/stemedb-api/Cargo.toml: Add serde_qs dependency
- crates/stemedb-api/src/extractors.rs: New QsQuery extractor (117 lines)
- crates/stemedb-api/src/handlers/aphoria/corpus.rs: Use QsQuery, broaden prefix
- crates/stemedb-api/src/lib.rs: Export extractors module
Also includes: Scale-adaptive thresholds, wiki corpus extraction,
documentation updates, and dashboard UI improvements from prior work.
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>