refactor(mcp): drop fable_ prefix from tool names; rebrand to Scribe

MCP clients see tools namespaced by the server's local name already
(mcp__<server>__<tool>), so the fable_ prefix on every tool name was
redundant and ate tokens in the model's tool list.

Tools renamed (34 total):
  fable_search → search
  fable_list_notes / get_note / create_note / update_note / delete_note → list_notes / ...
  fable_list_tasks / get_task / create_task / update_task / add_task_log → list_tasks / ...
  fable_list_projects / get_project / create_project / update_project → list_projects / ...
  fable_list_milestones / create_milestone / update_milestone → list_milestones / ...
  fable_list_events / create_event / get_event / update_event / delete_event → list_events / ...
  fable_list_tags → list_tags
  fable_get_recent → get_recent
  fable_list_persons / create_person / update_person → list_persons / ...
  fable_list_places / create_place / update_place → list_places / ...
  fable_list_lists / create_list / update_list → list_lists / ...

Also rebranded in MCP scope:
  FastMCP("fable", ...) → FastMCP("scribe", ...)
  auth realm "fable-mcp" → "scribe-mcp"
  ASGI scope key fable_user_id → scribe_user_id
  ContextVar label fable_mcp_user_id → scribe_mcp_user_id
  Tool docstrings "in Fable" / "Fable task" → "in Scribe" / "Scribe task"
  Server _INSTRUCTIONS prose

Deliberately kept:
  - The internal Python package name `fabledassistant` (per project naming
    convention — internal stays).
  - "Fabled Scribe" as the official product/brand name (page footer,
    smtp_from_name default).
  - References to the legacy `fable-mcp/` standalone package in docstrings
    explaining what we ported from — accurate until that directory is
    deleted in Phase 10.

Client impact: existing MCP registrations need
  claude mcp remove <name> && claude mcp add ...
once with a freshly-copied snippet from Settings → MCP Access. Claude
Code then re-discovers tools on connect — old conversations that
referenced fable_* tool names will see "tool not found" on those calls
until updated.

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

src/fabledassistant/mcp/tools/milestones.py

@@ -15,8 +15,8 @@ from fabledassistant.mcp._context import current_user_id
 from fabledassistant.services import milestones as milestones_svc
 
 
-async def fable_list_milestones(project_id: int) -> dict:
-    """List milestones for a Fable project, ordered by order_index.
+async def list_milestones(project_id: int) -> dict:
+    """List milestones for a Scribe project, ordered by order_index.
 
     Returns id, title, description, status (active/done), order_index,
     and task counts.
@@ -26,13 +26,13 @@ async def fable_list_milestones(project_id: int) -> dict:
     return {"milestones": rows}
 
 
-async def fable_create_milestone(
+async def create_milestone(
     project_id: int,
     title: str,
     description: str = "",
     status: str = "active",
 ) -> dict:
-    """Create a milestone within a Fable project.
+    """Create a milestone within a Scribe project.
 
     Args:
         project_id: The project this milestone belongs to (required).
@@ -51,7 +51,7 @@ async def fable_create_milestone(
     return milestone.to_dict()
 
 
-async def fable_update_milestone(
+async def update_milestone(
     project_id: int,
     milestone_id: int,
     title: str = "",
@@ -59,7 +59,7 @@ async def fable_update_milestone(
     status: str = "",
     order_index: int = -1,
 ) -> dict:
-    """Update a Fable milestone. Only explicitly provided fields are changed.
+    """Update a Scribe milestone. Only explicitly provided fields are changed.
 
     Args:
         project_id: Project the milestone belongs to (preserved for API parity;
@@ -88,8 +88,8 @@ async def fable_update_milestone(
 
 def register(mcp) -> None:
     for fn in (
-        fable_list_milestones,
-        fable_create_milestone,
-        fable_update_milestone,
+        list_milestones,
+        create_milestone,
+        update_milestone,
     ):
         mcp.tool(name=fn.__name__)(fn)