refactor: rename package fabledassistant -> scribe (code-only)

Renames src/fabledassistant -> src/scribe and all imports, plus the
default DB name and DB user/password (fabled -> scribe) in config +
compose. 952 refs / 154 files. Reverses the old 'internal name stays
fabledassistant' convention.

Code-only: live databases are still physically named 'fabledassistant'.
Deployed environments must set POSTGRES_DB / POSTGRES_USER (or rename the
DB) since the defaults now resolve to 'scribe'. Repo (FabledScribe), git
host (fabledsword), MCP (fabled-git) and the image name (fabledscribe)
are intentionally unchanged.

ruff check src/ clean locally; CI (typecheck + pytest) is the gate.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tests/test_mcp_endpoint.py

@@ -15,7 +15,7 @@ from unittest.mock import AsyncMock, MagicMock, patch
 
 import pytest
 
-from fabledassistant.app import create_app
+from scribe.app import create_app
 
 
 async def _send_request(
@@ -73,7 +73,7 @@ async def test_mcp_endpoint_unauthenticated_returns_401():
 async def test_mcp_endpoint_invalid_token_returns_401():
     app = create_app()
     with patch(
-        "fabledassistant.mcp.auth.lookup_key",
+        "scribe.mcp.auth.lookup_key",
         AsyncMock(return_value=None),
     ):
         status, _ = await _send_request(
@@ -107,7 +107,7 @@ async def test_mcp_endpoint_valid_token_passes_auth():
     }).encode()
     async with app.mcp_instance.session_manager.run():
         with patch(
-            "fabledassistant.mcp.auth.lookup_key",
+            "scribe.mcp.auth.lookup_key",
             AsyncMock(return_value=fake_key),
         ):
             status, _ = await _send_request(