fix(#1195): execution resolves a skill identity with ordinary discovery

Review finding (gpt-6-astra, triad): the liveness read, reconcile_extension and
the extension child had moved from discover_skills to
discover_selected_skill_candidates, the repair/publication resolver that opts a
manifestless directory in as a hidden ambiguity. A reviewed extension beside a
same-named manifestless directory became a collision placeholder: reconcile
unloaded it and dispatch refused it. The execution callers now use
discover_skill_identity — one identity under ORDINARY discovery semantics, the
same inventory find_skill reads — and the strict resolver stays with
repair/publication. Regression: tests/test_extension_manifestless_neighbour.py
(fails on the previous tree).

Also from this round: enabled_skill_conflicts reads skill.conflicts so a
SkillPeer is a valid subject (gpt-5.6-sol; differential test added), and
docs/MODEL_SEND_OBSERVABILITY.md names startup_historical_audit.py as the seal
reconciliation owner instead of the removed server_maintenance sweep (grok,
scope). FACADE_INVENTORY regenerated for the new re-export.

docs/MODEL_SEND_OBSERVABILITY.md

@@ -2,7 +2,9 @@
 
 The physical-send observability contract is implemented in
 `ouroboros/model_send_seal.py`, wired at
-`llm_attempt._candidate_before_dispatch` and swept from `server_maintenance`;
+`llm_attempt._candidate_before_dispatch` and swept by the session-custodied
+history child `ouroboros/startup_historical_audit.py` (launched after
+supervisor readiness, off the readiness path);
 `tests/test_model_send_seal.py` verifies it. The claim is deliberately narrow:
 a reconstruction mismatch is an observability fact, not a dispatch gate.
 
@@ -109,8 +111,9 @@ bounded, local, and on the same drive the record was just written to.
 
 ### 3.3 Reverse direction (audit, `model_send` only)
 
-A bounded reconciliation sweep (rides the existing startup-sweep family in
-`server_maintenance`, not a new scheduler):
+A bounded reconciliation sweep (runs inside the session-custodied history
+child `startup_historical_audit.py`, started by `server.py::_run_supervisor`
+after readiness — not on the readiness path, not a new scheduler):
 
 - every `model_send` seal ⟶ exactly one attempt row in the usage-accounting
   replay (any terminal state, including refused-before-dispatch);
@@ -220,8 +223,9 @@ from "our two copies agree" to "the durable record agrees with the wire".
 - `model_send_seal.py` stamps the physical-candidate manifest, reads back the
   durable projection, writes typed mismatch facts and reconciles both join
   directions. The seal is an additive key under the existing manifest schema.
-- `server_maintenance.py` runs the bounded reconciliation through the existing
-  startup sweep. Unknown accounting evidence does not become an orphan claim;
+- `startup_historical_audit.py` runs the bounded reconciliation as one
+  session-custodied child per generation, launched after supervisor readiness
+  (#1195 F1). Unknown accounting evidence does not become an orphan claim;
   the sweep records facts without deleting records or fabricating attempts.
 - `tests/test_model_send_seal.py` covers reconstruction, typed divergence,
   non-blocking dispatch and reverse joins. Compacted history is resolved through

docs/inventories/FACADE_INVENTORY.md

@@ -2,7 +2,7 @@
 
 AST-derived inventory of compatibility facades, regenerated by `python scripts/regenerate_inventories.py`. Do not edit. A facade row is any runtime module whose top-level `from <population module> import ...` statements carry the `noqa: F401` re-export marker — the codebase's declared "this binding exists for its binding, not for this module's own use" convention (reference FACADE_CONSUMERS method). Leaf domains come from `ouroboros/domains.toml`; a leaf outside the facade's domain is marked ✗ (that edge also appears in the manifest's pinned direction matrix). `tests/test_generated_inventories.py` pins byte-identity, so any re-export surface change must regenerate this file.
 
-- facade modules: **60**; marked re-export bindings: **2312**; cross-domain facade→leaf pairs: **132**
+- facade modules: **60**; marked re-export bindings: **2313**; cross-domain facade→leaf pairs: **132**
 
 | facade | domain | bindings | leaves |
 |---|---|---:|---|
@@ -12,7 +12,7 @@ AST-derived inventory of compatibility facades, regenerated by `python scripts/r
 | `ouroboros/config.py` | D12 | 133 | `ouroboros/model_slots.py` (17)<br>`ouroboros/provider_models.py` (6 ✗D02)<br>`ouroboros/review_model_routes.py` (10)<br>`ouroboros/runtime_limits.py` (62)<br>`ouroboros/settings_defaults.py` (19)<br>`ouroboros/settings_integrity.py` (4)<br>`ouroboros/settings_scales.py` (13)<br>`ouroboros/update_channels.py` (2) |
 | `ouroboros/context.py` | D03 | 4 | `ouroboros/context_runtime_facts.py` (4) |
 | `ouroboros/delegate_custody.py` | D07 | 10 | `ouroboros/delegate_custody_reconcile.py` (9)<br>`ouroboros/delegate_evidence.py` (1) |
-| `ouroboros/extension_loader.py` | D14 | 100 | `ouroboros/contracts/plugin_api.py` (7 ✗D19)<br>`ouroboros/extension_child_catalog.py` (8)<br>`ouroboros/extension_companion.py` (3)<br>`ouroboros/extension_import_staging.py` (6)<br>`ouroboros/extension_isolated_deps.py` (4)<br>`ouroboros/extension_liveness.py` (8)<br>`ouroboros/extension_plugin_api.py` (6)<br>`ouroboros/extension_registry_state.py` (20)<br>`ouroboros/extension_surface_names.py` (12)<br>`ouroboros/extension_ui_validation.py` (5)<br>`ouroboros/gateway/host_service.py` (1 ✗D11)<br>`ouroboros/provider_models.py` (1 ✗D02)<br>`ouroboros/skill_loader.py` (14)<br>`ouroboros/skill_token.py` (1)<br>`ouroboros/tools/skill_exec.py` (1)<br>`ouroboros/utils.py` (3 ✗D18) |
+| `ouroboros/extension_loader.py` | D14 | 101 | `ouroboros/contracts/plugin_api.py` (7 ✗D19)<br>`ouroboros/extension_child_catalog.py` (8)<br>`ouroboros/extension_companion.py` (3)<br>`ouroboros/extension_import_staging.py` (6)<br>`ouroboros/extension_isolated_deps.py` (4)<br>`ouroboros/extension_liveness.py` (8)<br>`ouroboros/extension_plugin_api.py` (6)<br>`ouroboros/extension_registry_state.py` (20)<br>`ouroboros/extension_surface_names.py` (12)<br>`ouroboros/extension_ui_validation.py` (5)<br>`ouroboros/gateway/host_service.py` (1 ✗D11)<br>`ouroboros/provider_models.py` (1 ✗D02)<br>`ouroboros/skill_loader.py` (15)<br>`ouroboros/skill_token.py` (1)<br>`ouroboros/tools/skill_exec.py` (1)<br>`ouroboros/utils.py` (3 ✗D18) |
 | `ouroboros/gateway/_helpers.py` | D11 | 2 | `ouroboros/jsonl_tail.py` (2 ✗D18) |
 | `ouroboros/gateway/contracts.py` | D11 | 7 | `ouroboros/gateway/decision_contracts.py` (2)<br>`ouroboros/gateway/history_contracts.py` (1)<br>`ouroboros/gateway/schedule_contracts.py` (4) |
 | `ouroboros/gateway/history.py` | D11 | 1 | `ouroboros/gateway/cost_breakdown.py` (1) |

ouroboros/extension_liveness.py

@@ -17,7 +17,7 @@ from ouroboros.extension_registry_state import _extensions, _load_failures, _loc
 from ouroboros.skill_loader import (
     LoadedSkill,
     _sanitize_skill_name,
-    discover_selected_skill_candidates,
+    discover_skill_identity,
     grant_status_for_skill,
     skill_conflict_status,
 )
@@ -191,7 +191,7 @@ def runtime_state_for_skill_name(
     elif skills is not None:
         selected = list(skills)
     else:
-        selected = discover_selected_skill_candidates(drive_root, skill_name, repo_path=resolved_repo_path)
+        selected = discover_skill_identity(drive_root, skill_name, repo_path=resolved_repo_path)
     peer_projection = list(skills) if skills is not None else list(
         discover_skill_peers(drive_root, repo_path=resolved_repo_path)
     )

ouroboros/extension_loader.py

@@ -132,7 +132,7 @@ from ouroboros.extension_surface_names import (
     extension_surface_name,  # noqa: F401
     parse_extension_surface_name,  # noqa: F401
 )
-from ouroboros.skill_loader import _SKILL_DIR_CACHE_NAMES, _sanitize_skill_name, LoadedSkill, SkillPayloadUnreadable, compute_content_hash, discover_skills, discover_selected_skill_candidates, find_skill, grant_status_for_skill, requested_core_setting_keys, skill_conflict_status, skill_review_gate, skill_state_dir, skill_state_dir_path  # noqa: F401
+from ouroboros.skill_loader import _SKILL_DIR_CACHE_NAMES, _sanitize_skill_name, LoadedSkill, SkillPayloadUnreadable, compute_content_hash, discover_skills, discover_selected_skill_candidates, discover_skill_identity, find_skill, grant_status_for_skill, requested_core_setting_keys, skill_conflict_status, skill_review_gate, skill_state_dir, skill_state_dir_path  # noqa: F401
 from ouroboros.skill_token import SkillToken  # noqa: F401
 from ouroboros.tools.skill_exec import _scrub_env  # noqa: F401
 from ouroboros.utils import atomic_write_json, read_json_dict, utc_now_iso  # noqa: F401
@@ -323,7 +323,7 @@ def reconcile_extension(
         from ouroboros.config import get_skills_repo_path
 
         resolved_repo_path = get_skills_repo_path() if repo_path is None else repo_path
-        peers = list(skills) if skills is not None else discover_selected_skill_candidates(
+        peers = list(skills) if skills is not None else discover_skill_identity(
             drive_root, skill_name, repo_path=resolved_repo_path
         )
         if selected_skill is not None:

ouroboros/extension_process_runner.py

@@ -865,7 +865,7 @@ def _load_child_extension(skill_name: str, drive_root: pathlib.Path, repo_dir: p
     from ouroboros.config import load_settings
     from ouroboros.extension_loader import load_extension
     from ouroboros.settings_integrity import _next_task_setting
-    from ouroboros.skill_loader import discover_selected_skill_candidates
+    from ouroboros.skill_loader import discover_skill_identity
 
     def settings_reader():
         live = load_settings()
@@ -876,7 +876,7 @@ def _load_child_extension(skill_name: str, drive_root: pathlib.Path, repo_dir: p
         return {**{key: value for key, value in live.items() if not _next_task_setting(key)},
                 **task_settings}
 
-    skills = discover_selected_skill_candidates(drive_root, skill_name, repo_path=str(skills_repo_path))
+    skills = discover_skill_identity(drive_root, skill_name, repo_path=str(skills_repo_path))
     skill = next((item for item in skills if item.name == skill_name), None)
     if skill is None:
         raise ExtensionProcessError(f"extension skill {skill_name!r} is missing")

ouroboros/skill_conflicts.py

@@ -23,7 +23,7 @@ def enabled_skill_conflicts(skill: Any, skills: List[Any]) -> List[str]:
     A declaration on either side is authoritative, so one-sided manifests are
     enforced symmetrically. Missing and disabled peers are deliberately inert.
     """
-    declared = set(skill.manifest.conflicts or [])
+    declared = set(skill.conflicts or ())
     conflicts = {
         peer.name
         for peer in skills

ouroboros/skill_loader.py

@@ -1406,6 +1406,34 @@ def discover_selected_skill_candidates(
     )
 
 
+def discover_skill_identity(
+    drive_root: pathlib.Path,
+    name: str,
+    *,
+    repo_path: str | None = None,
+) -> List[LoadedSkill]:
+    """Load one identity with ORDINARY discovery semantics, nothing else read.
+
+    Same inventory and collision rules as ``discover_skills`` restricted to one
+    canonical name — no manifestless opt-in, so a directory without a manifest
+    beside a valid skill of the same name stays invisible here exactly as it is
+    to passive discovery. This is the resolver every EXECUTION caller uses
+    (liveness, reconcile, the extension child); the repair/publication lanes
+    keep ``discover_selected_skill_candidates`` and its deliberately stricter
+    manifestless ambiguity.
+    """
+    if repo_path is None:
+        from ouroboros.config import get_skills_repo_path
+
+        repo_path = get_skills_repo_path()
+    safe = _sanitize_skill_name(name)
+    candidates = tuple(
+        item for item in _skill_location_inventory(drive_root, repo_path=repo_path)
+        if item.name == safe
+    )
+    return _load_skill_location_candidates(candidates, drive_root=drive_root)
+
+
 def find_skill(
     drive_root: pathlib.Path,
     name: str,
@@ -1414,8 +1442,7 @@ def find_skill(
 ) -> Optional[LoadedSkill]:
     """Return one skill by name, including broken manifests with ``load_error``."""
     safe = _sanitize_skill_name(name)
-    candidates = tuple(item for item in _skill_location_inventory(drive_root, repo_path=repo_path) if item.name == safe)
-    for skill in _load_skill_location_candidates(candidates, drive_root=drive_root):
+    for skill in discover_skill_identity(drive_root, name, repo_path=repo_path):
         if skill.name == safe:
             return skill
     return None
@@ -1560,7 +1587,7 @@ __all__ = [
     "AutoGrantOutcome", "LoadedSkill", "HASH_EXEMPT_CONTROL_FILENAMES",
     "SkillReviewState", "auto_grant_if_enabled",
     "VALID_REVIEW_STATUSES", "compute_content_hash", "reduce_skill_content_hash", "discover_skills",
-    "discover_selected_skill_candidates", "find_skill",
+    "discover_selected_skill_candidates", "discover_skill_identity", "find_skill",
     "enabled_skill_conflicts", "skill_conflict_status",
     "grant_status_for_skill", "is_self_authored_skill_dir", "list_available_for_execution",
     "load_enabled", "load_review_state", "load_skill_grants", "load_skill",

tests/test_extension_manifestless_neighbour.py

@@ -0,0 +1,66 @@
+"""Execution discovery ignores a manifestless directory beside a valid skill.
+
+Regression for the #1195 F4 review finding: the execution callers (liveness,
+reconcile, the extension child) must resolve a selected identity with ORDINARY
+discovery semantics. Only the repair/publication lane may opt a manifestless
+directory in as a hidden ambiguity; a reviewed extension next to a same-named
+directory without a manifest keeps executing.
+"""
+from __future__ import annotations
+
+import pathlib
+
+from ouroboros import extension_loader
+from ouroboros.skill_loader import (
+    discover_selected_skill_candidates,
+    discover_skill_identity,
+)
+
+from tests._extension_loader_shared import _prepare_extension
+from tests._extension_loader_shared import (  # noqa: F401  (autouse fixture applies on import)
+    _clear_loader_state,
+)
+
+
+def _manifestless_neighbour(drive_root: pathlib.Path, name: str) -> pathlib.Path:
+    # Same canonical identity, no SKILL.md: the layout the publish preflight
+    # treats as ambiguous and ordinary discovery treats as absent.
+    neighbour = drive_root / "skills" / "external" / name
+    neighbour.mkdir(parents=True)
+    (neighbour / "notes.txt").write_text("not a skill\n", encoding="utf-8")
+    return neighbour
+
+
+def test_manifestless_neighbour_is_invisible_to_execution_discovery(tmp_path):
+    loaded, repo_root, drive_root = _prepare_extension(
+        tmp_path, "neighbour_case", "def register(api):\n    pass\n", permissions=[],
+    )
+    _manifestless_neighbour(drive_root, loaded.name)
+
+    ordinary = discover_skill_identity(drive_root, loaded.name, repo_path=str(repo_root))
+    assert [s.identity_collision for s in ordinary] == [False]
+    assert ordinary[0].skill_dir.resolve() == loaded.skill_dir.resolve()
+
+    # The stricter repair/publication resolver still sees the ambiguity.
+    strict = discover_selected_skill_candidates(drive_root, loaded.name, repo_path=str(repo_root))
+    assert len(strict) == 2 and all(s.identity_collision for s in strict)
+
+
+def test_reviewed_extension_still_loads_beside_a_manifestless_neighbour(tmp_path):
+    loaded, repo_root, drive_root = _prepare_extension(
+        tmp_path, "neighbour_exec", "def register(api):\n    pass\n", permissions=[],
+    )
+    _manifestless_neighbour(drive_root, loaded.name)
+
+    state = extension_loader.reconcile_extension(
+        loaded.name, drive_root, lambda: {}, repo_path=str(repo_root),
+    )
+    assert state["action"] == "extension_loaded", state
+    assert state["live_loaded"] is True
+
+    runtime = extension_loader.runtime_state_for_skill_name(
+        loaded.name, drive_root, repo_path=str(repo_root),
+    )
+    assert runtime["live_loaded"] is True
+    assert runtime.get("identity_collision", False) is False
+    assert runtime["reason"] != "missing"

tests/test_extension_process_runner.py

@@ -113,14 +113,14 @@ def test_child_extension_load_reuses_one_discovered_peer_snapshot(tmp_path, monk
         permissions=[],
     )
     calls = 0
-    real_discover = skill_loader.discover_selected_skill_candidates
+    real_discover = skill_loader.discover_skill_identity
 
     def counted_discover(*args, **kwargs):
         nonlocal calls
         calls += 1
         return real_discover(*args, **kwargs)
 
-    monkeypatch.setattr(skill_loader, "discover_selected_skill_candidates", counted_discover)
+    monkeypatch.setattr(skill_loader, "discover_skill_identity", counted_discover)
     monkeypatch.setattr("ouroboros.config.load_settings", lambda: {})
 
     runner._load_child_extension(

tests/test_extension_reconcile.py

@@ -166,14 +166,14 @@ def test_reconcile_loads_selected_payload_without_full_peer_discovery(tmp_path,
         permissions=[],
     )
     calls = 0
-    real_discover = extension_loader.discover_selected_skill_candidates
+    real_discover = extension_loader.discover_skill_identity
 
     def counted_discover(*args, **kwargs):
         nonlocal calls
         calls += 1
         return real_discover(*args, **kwargs)
 
-    monkeypatch.setattr(extension_loader, "discover_selected_skill_candidates", counted_discover)
+    monkeypatch.setattr(extension_loader, "discover_skill_identity", counted_discover)
 
     state = extension_loader.reconcile_extension(
         loaded.name,

tests/test_skill_peer_inventory_differential.py

@@ -245,3 +245,24 @@ def test_skill_peer_is_immutable_and_non_executable():
     assert not hasattr(peer, "content_hash")
     assert not hasattr(peer, "review")
     assert not hasattr(peer, "manifest")
+
+
+def test_a_peer_is_a_valid_subject_of_the_conflict_projection(tmp_path):
+    """Duck typing holds on BOTH sides: a SkillPeer subject reaches the same verdict.
+
+    `enabled_skill_conflicts` reads `skill.conflicts`, never `skill.manifest`,
+    because `SkillPeer` deliberately has no manifest.
+    """
+    drive = tmp_path / "drive"
+    skills = drive / "skills" / "external"
+    _write(skills / "declares", _manifest("declares", conflicts=("target",)))
+    _write(skills / "target", _manifest("target"))
+    save_enabled(drive, "declares", True)
+    save_enabled(drive, "target", True)
+    full = {s.name: s for s in discover_skills(drive, repo_path="")}
+    peers = {p.name: p for p in discover_skill_peers(drive, repo_path="")}
+    for name in ("declares", "target"):
+        as_full = skill_conflict_status(full[name], list(peers.values()))
+        as_peer = skill_conflict_status(peers[name], list(peers.values()))
+        assert as_peer is not None, name
+        assert as_full == as_peer, name