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_embeddings.py

@@ -7,7 +7,7 @@ from unittest.mock import AsyncMock, MagicMock, patch
 
 import pytest
 
-from fabledassistant.services.embeddings import (
+from scribe.services.embeddings import (
     _cosine_similarity, get_embedding,
 )
 
@@ -54,7 +54,7 @@ async def test_get_embedding_returns_list_of_floats():
     fake_embedder = MagicMock()
     fake_embedder.embed = MagicMock(return_value=iter([fake_vec]))
     with patch(
-        "fabledassistant.services.embeddings._get_model",
+        "scribe.services.embeddings._get_model",
         AsyncMock(return_value=fake_embedder),
     ):
         out = await get_embedding("hello world")
@@ -71,7 +71,7 @@ async def test_get_embedding_ignores_legacy_model_param():
     fake_embedder = MagicMock()
     fake_embedder.embed = MagicMock(return_value=iter([fake_vec]))
     with patch(
-        "fabledassistant.services.embeddings._get_model",
+        "scribe.services.embeddings._get_model",
         AsyncMock(return_value=fake_embedder),
     ):
         out = await get_embedding("x", model="ignored-model-name")
@@ -83,7 +83,7 @@ async def test_get_embedding_propagates_model_load_failures():
     """If fastembed can't initialize, the error propagates — callers catch
     and degrade to keyword search."""
     with patch(
-        "fabledassistant.services.embeddings._get_model",
+        "scribe.services.embeddings._get_model",
         AsyncMock(side_effect=RuntimeError("model load failed")),
     ):
         with pytest.raises(RuntimeError, match="model load failed"):