fix(scribe): a delete must not depend on the lookup that names it (#3273)

CI caught the naming work reaching for Postgres from the unit lane, and the
connection error was the symptom of a real design fault rather than a test
gap: reading the title BEFORE the delete put a live query on the delete path,
so a lookup that failed would have stopped the delete happening.

That is a decoration breaking its payload — the same mistake just fixed in
rules_etag, made again two commits later. Every title lookup now fails open:
delete_task, delete_note, delete_milestone, delete_snippet and rule_history
lose the name, never the operation.

The five unit tests mock the lookup rather than reaching for a database, and
delete_note gains one asserting the delete still happens when the lookup
raises — the behaviour, not just the absence of a crash.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

tests/test_mcp_tool_rulebooks.py

@@ -470,6 +470,11 @@ async def test_rule_history_lists_without_the_heavy_text():
     with patch(
         "scribe.mcp.tools.rulebooks.rulebooks_svc.list_rule_versions",
         AsyncMock(return_value=[_fake_version(), _fake_version(id=4)]),
+    ), patch(
+        "scribe.mcp.tools.rulebooks.rulebooks_svc.get_rule",
+        AsyncMock(return_value=fake_rule(
+            id=100, title="The runner has no bash", statement="s", topic_id=10,
+        )),
     ):
         from scribe.mcp.tools.rulebooks import rule_history
         out = await rule_history(rule_id=100)
@@ -503,6 +508,11 @@ async def test_rule_history_says_an_empty_history_is_ordinary():
     with patch(
         "scribe.mcp.tools.rulebooks.rulebooks_svc.list_rule_versions",
         AsyncMock(return_value=[]),
+    ), patch(
+        "scribe.mcp.tools.rulebooks.rulebooks_svc.get_rule",
+        AsyncMock(return_value=fake_rule(
+            id=100, title="The runner has no bash", statement="s", topic_id=10,
+        )),
     ):
         from scribe.mcp.tools.rulebooks import rule_history
         out = await rule_history(rule_id=100)