Qwen3 retrieval pilot continued: balanced backfill + hybrid search

Result

• Branch: wip/openrouter-qwen3-embedding-pilot
• New commit: c2d9b4c feat(retrieval): add balanced Qwen backfill and hybrid eval
• Qwen3 coverage after balanced backfill: 586 docs / 3878 chunks, min/max dim 4096.
• Added backfill controls: --skip-existing, --source, --exclude-source, --max-chunks-per-doc, --max-total-chunks.
• Added chunk fulltext index: maester_chunk_fulltext.
• Added vector+chunk-fulltext hybrid search and wired Maester recall to use it.
• Added eval script: scripts/eval_vector_retrieval.py.

Eval Files

• context/evaluations/2026-06-20-qwen3-vector-pilot.json
• context/evaluations/2026-06-20-qwen3-vector-pilot-balanced.json
• context/evaluations/2026-06-20-qwen3-hybrid-pilot-balanced.json

Observations

• Tiro-only pilot was misleading: generic/system queries all returned recent Tiro transcripts.
• Balanced AI/document-source backfill shifted top docs to Claude/Gemini/Codex/design docs.
• Hybrid retrieval improved exact-name workflows for Tiro, CPC/nginx, and GraphRAG.
• Remaining gap: current repo-local Qwen/OpenRouter pivot docs must be ingested into Maester too; otherwise recall cannot retrieve them as Maester documents.

Dirty State

• data/action_lifecycle_audit.jsonl remains dirty as unrelated runtime audit log and was not committed.