Fix Newsreader build errors

The Newsreader migration from Biz/ to Omni/ is incomplete. Code was written but never tested/built.

Current State

• DbTest.hs: ✅ Passes (7 tests)
• FetcherTest.hs: ❌ Build fails (15+ type errors in Fetcher.hs)
• FetchTest.hs: ❌ Build fails (same dep on Fetcher.hs)

Fixes Already Made

1. Removed incorrect -- : dep Omni/Newsreader/*.hs lines from FetcherTest.hs and Ingest.hs 2. Added modern-uri dep and DataKinds extension to Extractor.hs and Fetcher.hs 3. Fixed Req.mkURI -> URI.mkURI usage in Extractor.hs 4. Fixed HTTP status code check in Extractor.hs 5. Removed unused import and binding in Extractor.hs

Remaining Work

Fetcher.hs has many type errors (GHC-83865) around lines 96, 163-221. These appear to be mismatches between the feed library's API and how the code uses it. The code was written assuming certain types but never compiled.

Key errors:

• Line 96: Status code type mismatch
• Lines 163-221: RSS/Atom field accessor type mismatches

Files to Fix

• Omni/Newsreader/Fetcher.hs - main file needing fixes
• After Fetcher.hs builds, retest FetcherTest.hs and FetchTest.hs

Verification

bild --test Omni/Newsreader/DbTest.hs
bild --test Omni/Newsreader/FetcherTest.hs
bild --test Omni/Newsreader/FetchTest.hs

Related

• Parent task: t-488 (LLM Newsreader)