test(410): one guidance-topic registry, and a loss guard before anything moves (#4028)

Step 1 of milestone 410 "One owner per piece of guidance". The later steps
delete duplicate copies of agent guidance; this guard stops the last copy of
a topic going with them.

- tests/test_guidance_ownership.py holds the registry: 30 topics from the
  ownership map in decision #4027, each with its owner and marker phrases,
  and one definition of a delivered surface (_INSTRUCTIONS, tool docstrings,
  each skill, the static context, the adapter commands, the live session
  context).
- The loss guard: every topic is stated in full, with all its markers
  together, on at least one delivered surface. A miss names the nearest
  partial match.
- The owner column is recorded but not asserted yet; step 6 adds the
  exactly-one-owner guard once the moves are done.
- test_the_loss_guard_can_fail proves split and absent markers are reported
  (rule 167).
- The old DISPLACED_TOPICS list in test_instruction_surfaces_agree is folded
  in, so there is one list rather than two.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

tests/test_instruction_surfaces_agree.py

@@ -211,50 +211,10 @@ def test_floor_names_the_snippet_recording_triggers():
         )
 
 
-# Topics displaced from _INSTRUCTIONS when it was cut to fit the fold. Each
-# must remain stated on at least one DELIVERED surface: a tool docstring
-# (arrives with the tool schema), the plugin static context (always arrives),
-# or a bundled skill (arrives on trigger match). Keyed by a phrase distinctive
-# enough that its disappearance means the guidance is gone, not reworded —
-# update the phrase alongside a deliberate rewording.
-DISPLACED_TOPICS = {
-    "supersedes": "supersedes",
-    "trash is recoverable": "deleted_batch_id",
-    "duplicate gate": "duplicate",
-    "systems tag-as-you-write": "system_ids",
-    "reference note vs dev-log": "reference note",
-    "work-logs over body rewrites": "add_task_log",
-    "rule homes / altitude": "create_project_rule",
-    "rules vs other entities": "standing instruction",
-    "shared records are suggestions": "shared",
-    "processes run verbatim": "verbatim",
-    "snippet reuse reflex": "when_to_use",
-    "compaction at seams": "compact",
-    "plans are milestones": "start_planning",
-    "scope to the entered project": "cross-project",
-    "project bootstrap needs confirmation": "never guessing a project",
-}
-
-
-def test_displaced_topics_live_on_a_delivered_surface():
-    corpus = ""
-    for p in (ROOT / "src" / "scribe" / "mcp" / "tools").glob("*.py"):
-        corpus += p.read_text()
-    corpus += (ROOT / "plugin" / "hooks" / "scribe_static_context.md").read_text()
-    for p in (ROOT / "plugin" / "skills").rglob("SKILL.md"):
-        corpus += p.read_text()
-    corpus = corpus.lower()
-    missing = [
-        f"{topic} (phrase: {phrase!r})"
-        for topic, phrase in DISPLACED_TOPICS.items()
-        if phrase.lower() not in corpus
-    ]
-    assert not missing, (
-        f"guidance displaced from _INSTRUCTIONS has fallen off every delivered "
-        f"surface (tool docstrings / static context / skills): {missing}. It "
-        f"was cut from _INSTRUCTIONS deliberately (#2562) on the premise it "
-        f"lives elsewhere — restore it somewhere that delivers."
-    )
+# The "displaced from _INSTRUCTIONS" topics (#2562) used to be listed here with
+# their own delivered-surface check. They are folded into the one topic registry
+# in tests/test_guidance_ownership.py (milestone 410), which covers every topic
+# of the ownership map and defines "delivered surface" once.
 
 
 def test_no_surface_names_the_push_without_stating_the_ask():