feat(mcp): make Scribe reflexively recall + scope reads to the active project

The MCP surface advertised writing well but recall poorly, and project
scoping had no anchor that survived past enter_project's snapshot:

- search / list_notes dropped the project_id their services already
  support, so a scoped search was impossible — every query swept all
  projects and bled unrelated work into the session.
- The tool descriptions were mechanical ("Semantic search over the
  user's notes and tasks") with no trigger telling Claude WHEN to reach
  for them; the server instructions were all write-discipline and said
  nothing about searching before answering or starting work.

Changes:
- search, list_notes: add project_id param, wired to the service.
- search, list_notes, list_tasks: trigger-worded descriptions that push
  passing the active project's id and reserve project_id=0 for a
  deliberate cross-project sweep.
- _INSTRUCTIONS: add a 'Reach for Scribe to RECALL, not just to record'
  block — search before answering/starting, check for an existing ticket
  before create_task, scope reads to the active project (which does not
  stick on the server).

Paired with always-on rule #75 in the FabledSword-family rulebook.

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

src/scribe/mcp/tools/tasks.py

@@ -37,7 +37,10 @@ async def list_tasks(
 
     Args:
         status: Filter by status — one of: todo, in_progress, done, cancelled. Omit for all.
-        project_id: Filter to a specific project. Use 0 for no filter.
+        project_id: Filter to a specific project. PASS THE ACTIVE PROJECT'S ID
+            whenever a project is in scope so you list that project's tasks, not
+            every project's. 0 = no filter (all projects — use only for a
+            deliberate cross-project view).
         kind: Filter by task kind — 'work' or 'plan'. Omit (empty) for all kinds.
 
     Results are ordered by last-updated descending.