feat(training): Style Studio — upload, rich corpus, lessons, curator portrait, chat

Six-phase upgrade of /training from a read-only dashboard into a full
Style Studio for managing Daphna's style corpus.

- Upload Sheet on /training: file → proofread preview → commit (no more
  CLI-only `upload-training` skill).
- Rich corpus metadata: GET /api/training/corpus returns summary, outcome,
  key_principles, page_count, parties (regex), legal_citation, lessons_count.
  PATCH endpoint for chair edits. CorpusDetailDrawer with 4 tabs (details
  /content/lessons/patterns) replaces the bare table row.
- LLM metadata enrichment: style_metadata_extractor + MCP tools
  (style_corpus_enrich, style_corpus_pending_enrichment) fill summary
  /outcome/key_principles via claude_session (free, host-side).
- Per-decision lessons: new decision_lessons table + 4 REST endpoints +
  LessonsTab in drawer; hermes-curator now auto-posts findings as
  decision_lessons(source=curator).
- Curator Portrait tab: prompt rendered with link to Gitea, recent
  curator findings, style_analyzer training prompts, propose-change
  form that writes proposals to data/curator-proposals/ for manual
  chair review (no auto-mutation of the agent file).
- Style chat tab: SSE-streamed conversations with the style agent.
  New host-side pm2 service (legal-chat-service, port 8770) wraps
  claude CLI with stream-json + --resume continuation; FastAPI proxies
  via host.docker.internal. Zero API cost — uses chaim's claude.ai
  subscription. chat_conversations + chat_messages persist history.

Architecture: keeps the existing rule that claude_session only runs
on the host (not the container). The new legal-chat-service is the
canonical bridge between the container and the local CLI for the chat
feature; everything else (upload, metadata, lessons) stays within the
container's existing capabilities.

Audit script (scripts/audit_training_corpus.py) included for verifying
which corpus rows still need enrichment.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

mcp-server/src/legal_mcp/tools/training_enrichment.py

@@ -0,0 +1,85 @@
+"""MCP tool wrappers for the style_corpus metadata-enrichment flow.
+
+The actual extractor lives in
+``legal_mcp.services.style_metadata_extractor``; this module just exposes
+it as MCP tools that the chair (or a future automation) can call from
+Claude Code.
+
+Why these tools matter: the upload pipeline (`/api/training/upload` →
+`_process_proofread_training`) inserts a style_corpus row with
+``summary=''``, ``outcome=''``, ``key_principles=[]`` because LLM
+extraction can't run from the FastAPI container (no claude CLI there).
+This module fills that gap — call it from the host, where ``claude``
+CLI is available, and the row gets enriched.
+"""
+
+from __future__ import annotations
+
+import json
+from uuid import UUID
+
+from legal_mcp.services import db, style_metadata_extractor
+
+
+def _ok(payload) -> str:
+    return json.dumps({"ok": True, **payload}, ensure_ascii=False, default=str)
+
+
+def _err(msg: str) -> str:
+    return json.dumps({"ok": False, "error": msg}, ensure_ascii=False)
+
+
+async def extract_decision_metadata(corpus_id: str, overwrite: bool = False) -> str:
+    """חילוץ מטא-דאטה (summary, outcome, key_principles, appeal_subtype) להחלטה בקורפוס הסגנון.
+
+    ברירת מחדל ``overwrite=False`` ממלא רק שדות ריקים. הזן ``overwrite=true``
+    כדי לרענן ערכים שכבר נכתבו.
+    """
+    try:
+        cid = UUID(corpus_id)
+    except ValueError:
+        return _err("corpus_id לא תקין")
+    try:
+        result = await style_metadata_extractor.extract_and_apply(cid, overwrite=overwrite)
+    except Exception as e:
+        return _err(str(e))
+    return _ok(result)
+
+
+async def list_corpus_pending_enrichment(limit: int = 50) -> str:
+    """רשימת רשומות style_corpus שחסר להן summary/outcome/key_principles — מועמדות להעשרה."""
+    pool = await db.get_pool()
+    async with pool.acquire() as conn:
+        rows = await conn.fetch(
+            """
+            SELECT id, decision_number, decision_date,
+                   length(full_text) AS chars,
+                   coalesce(summary, '') = '' AS missing_summary,
+                   coalesce(outcome, '') = '' AS missing_outcome,
+                   coalesce(jsonb_array_length(key_principles), 0) = 0 AS missing_principles
+            FROM style_corpus
+            WHERE coalesce(summary, '') = ''
+               OR coalesce(outcome, '') = ''
+               OR coalesce(jsonb_array_length(key_principles), 0) = 0
+            ORDER BY decision_date NULLS LAST
+            LIMIT $1
+            """,
+            limit,
+        )
+    items = [
+        {
+            "corpus_id": str(r["id"]),
+            "decision_number": r["decision_number"] or "",
+            "decision_date": str(r["decision_date"]) if r["decision_date"] else "",
+            "chars": r["chars"],
+            "missing": [
+                f for f, v in (
+                    ("summary", r["missing_summary"]),
+                    ("outcome", r["missing_outcome"]),
+                    ("key_principles", r["missing_principles"]),
+                ) if v
+            ],
+        }
+        for r in rows
+    ]
+    return _ok({"count": len(items), "items": items})