embedd: bump default to nomic-embed-text-v2-moe (475M MoE, 768d drop-in)

Local Ollama has three embedding models loaded:
  nomic-embed-text:latest        137M  768d  (previous default)
  nomic-embed-text-v2-moe:latest 475M  768d  (this commit's default)
  qwen3-embedding:latest         7.6B  4096d (would require dim change)

v2-moe is a drop-in upgrade — same 768 dim, 3.5× more params, MoE
architecture. Workers index doesn't need rebuilding, just future ingests
embed with the stronger model.

Run #005 result on the multi-coord stress suite:

  Diversity (same-role-across-contracts): 0.080 → 0.000 (n=9)
    → MoE is more discriminating: zero worker overlap across
      Milwaukee / Indianapolis / Chicago for shared role names.
      The geo + cert + skill context fully separates worker pools.
  Different-roles-same-contract: 0.013 → 0.036 (still ~96% diff)
  Determinism: 1.000 (unchanged)
  Verbatim handover: 4/4 (100%)
  Paraphrase handover: 4/4 (100%)

  200-worker swap: Jaccard 0.000 (unchanged — still perfect)

  Fresh-resume verify: STILL doesn't surface fresh workers in top-8.
    With v2-moe, distances increased (top-1 = 0.43–0.65 vs v1's 0.25–0.39)
    — the embedder is MORE discriminating, but the fresh worker's
    vector still doesn't outrank the 8th-best existing worker. Now
    suspect of being an HNSW post-build add issue (coder/hnsw
    incremental adds can land in hard-to-reach graph regions, not an
    embedder problem). Better embedder didn't fix it; needs a
    different strategy: full index rebuild after fresh adds, or
    explicit playbook-layer score boost for fresh workers, or
    hybrid (keyword + semantic) retrieval. Phase 3 investigation.

Cost: ingest is ~5× slower (workers 20s→100s; ethereal 35s→112s).
Acceptable for the quality jump on diversity. Real production with
incremental ingest won't pay this once-per-deploy.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

scripts/playbook_lift.sh

@@ -161,7 +161,7 @@ refresh_every = "1s"
 [embedd]
 bind = "127.0.0.1:3216"
 provider_url  = "http://localhost:11434"
-default_model = "nomic-embed-text"
+default_model = "nomic-embed-text-v2-moe"
 
 [vectord]
 bind = "127.0.0.1:3215"