fix(mcp): eliminate "No such tool available" race at agent wakeup

When Paperclip wakes the CEO and the model issues an mcp__legal-ai__*
call within ~10s of session init, Claude Code sometimes returns
"No such tool available" because the legal-ai MCP server hasn't
finished bringing up its tool catalog yet. Observed twice today on
CMPA precedent-extraction wakeups (sessions 9989fbaf and a9c61801);
the agent fell back to bash + .venv/bin/python and finished the work,
but the race needed fixing on the server side.

Three changes that close the window:

1. Lazy schema init (services/db.py + server.py)
   `init_schema()` was awaited inside the FastMCP lifespan, blocking
   the `initialize`/`tools/list` handshake until ~10 CREATE TABLE IF
   NOT EXISTS statements ran. Under contention (two CEOs waking at
   once for different companies) this stretched. Now the lifespan
   returns immediately and `get_pool()` runs the schema migrations
   exactly once on first DB access, guarded by an asyncio.Lock.
   tools/list is answered in milliseconds regardless of DB state.

2. Lazy heavy imports
   - services/embeddings.py: voyageai (~450ms) loaded only inside
     _get_client()
   - services/extractor.py: google.cloud.vision (~550ms) loaded only
     inside _get_vision_client() and _ocr_with_google_vision()
   These two were being imported at module top from
   legal_mcp.tools.documents -> services.processor -> services.{
   extractor,embeddings}, so the FastMCP server couldn't even start
   responding until both finished. Cold start dropped from 2.7s to
   1.17s end-to-end (init + tools/list response).

3. Agent-side warmup + retry guidance (.claude/agents/legal-ceo.md)
   Even with a fast server, the model can still race on the very
   first call. The precedent-extraction section now tells the CEO
   to call workflow_status as a warmup probe and to retry after a
   short sleep if it sees "No such tool available", before falling
   back to the python bypass.

Also expanded the precedent-tool whitelists on the sub-agents that
delegate halacha/library work (commits 4a9a6b7 + 7ee90dc added the
tools to the MCP server but only the CEO got them in its allowed
list). Added to: legal-researcher (full extraction set), legal-analyst
(library_get/list + halacha review), legal-writer (library lookups +
halacha_review), legal-qa (library_get + halacha_review), and the two
that the CEO was already missing (halacha_review, halachot_pending).

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

mcp-server/src/legal_mcp/services/embeddings.py

@@ -5,16 +5,18 @@ from __future__ import annotations
 import logging
 from typing import TYPE_CHECKING
 
-import voyageai
-
 from legal_mcp import config
 
 if TYPE_CHECKING:
+    import voyageai
     from PIL import Image as PILImage
 
 logger = logging.getLogger(__name__)
 
-_client: voyageai.Client | None = None
+# voyageai is imported lazily inside _get_client to keep MCP server startup
+# fast — loading voyageai eagerly costs ~450ms and Claude Code's first tool
+# call can hit a "No such tool available" race if the server isn't ready yet.
+_client: "voyageai.Client | None" = None
 
 # Per-call cap for multimodal_embed. POC ran 89 pages (~312K tokens)
 # in a single call comfortably; 50 leaves safe headroom for densely-
@@ -22,9 +24,10 @@ _client: voyageai.Client | None = None
 _MULTIMODAL_BATCH_SIZE = 50
 
 
-def _get_client() -> voyageai.Client:
+def _get_client() -> "voyageai.Client":
     global _client
     if _client is None:
+        import voyageai
         _client = voyageai.Client(api_key=config.VOYAGE_API_KEY)
     return _client