feat(harness): Onda 0b — setup workspace per-cliente + build LSH (D14a validato)

Repo workspace per-cliente tht-workspace-psd/ (git separato): 35 evidence Thoth
frontmatturate (da etl/docs/evidence/, non tutto etl/docs), psd.yaml con path
assoluti ancorati al repo, THT_DOCS_ROOT -> radice repo cliente. README documeta
il deployment shape (2 checkout + .env).

LSH build sul DWH reale (REST, VPN): 75737 valori / 491 colonne eligible -> indice
175M nel repo cliente. tht lsh query 'ablazione' -> 8 colonne (D14a non-collapsing
validato end-to-end: procedure_type, descrizione_procedura, intervento, ...).

Correzioni al piano eseguite durante l'implementazione:
- aggiunto 'tht schema introspect' (prerequisito di lsh build, omesso nel piano)
- uso -c (il cmd ha --config, non --workspace residuo)
- path assoluti nel psd.yaml (paths sono relativi alla CWD, non al file YAML)
- evidence corretta: solo etl/docs/evidence/ (35), non tutto etl/docs (895)

Test L2 riallineato: WORKSPACE -> psd.yaml nel repo cliente (non tht-test.yaml),
index_dir -> paths.indexes/'lsh', nome -> db_schema (non letterale 'datawarehouse').
Bug latente del test (path mismatch) mai emerso prima: ora PASS invece di SKIP.

Verifica: pytest 165 passed, 5 deselected; pytest -m l2 test_value_grounding_real PASS.

harness/README.md

@@ -33,6 +33,33 @@ Keys are never logged; URLs are fine. Rotate any key that appeared in chat.
 A workspace wires the relational DWH + the pgvector (dual-key) + embeddings + evidence.
 See `workspaces/tht.example.yaml`. `${THT_*}}` tokens expand from `.env`.
 
+### Per-customer workspace repo (deployment shape)
+
+ThothII is generic; **evidence content and LSH indexes are per-customer** and live in a
+**separate repo**, not copied into `harness/`. The deployment is two checkouts + one `.env`:
+
+```
+ThothII/                      generic harness (this repo)
+└── harness/                  tht CLI + .env (THT_* secrets, points at the customer repo)
+
+tht-workspace-<customer>/     per-customer workspace repo (separate git repo)
+├── <customer>.yaml           workspace YAML (paths ABSOLUTE, anchored here)
+├── evidence/                 curated evidence markdown (frontmatter-structured, by domain)
+├── artifacts/                derived artifacts (gitignored; regenerated by tht)
+├── indexes/                  LSH index (gitignored; regenerated by `tht lsh build`)
+└── sessions/                 per-session artifacts (gitignored)
+```
+
+`THT_DOCS_ROOT` in `.env` points at the **root** of the customer repo
+(`evidence.source_root` + `evidence.evidence_dir` resolve the curated folder).
+All `tht` commands take the customer workspace via `-c`:
+
+```bash
+tht schema introspect -c /path/to/tht-workspace-<customer>/<customer>.yaml
+tht lsh build        -c /path/to/tht-workspace-<customer>/<customer>.yaml
+tht session new      -c /path/to/tht-workspace-<customer>/<customer>.yaml
+```
+
 ## The workflow
 
 `workflow.yaml` is the **single source of workflow truth** (spec F2). Eight phases