feat(skills): unified read-merge + authoring/override MCP tools

Adds the merged read surface (api/skill_catalog_view.py) over synced +
local stores with origin discrimination and override precedence, and
extends the skill MCP tools with create_skill/update_skill/delete_skill
that dispatch by origin (edit local skills; create/update/remove local
overrides for cloud skills). Wired into api.mcp.create_mcp_server.
Full non-integration suite green (564 passed).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tests/test_skill_catalog_mcp.py

@@ -12,6 +12,7 @@ from api.skill_catalog_mcp import (
     SKILL_TOOL_NAMES,
     InvalidFlowTemplateError,
     MissingParameterError,
+    SkillAuthoringError,
     SkillCatalogError,
     SkillNotFoundError,
     register_skill_catalog_tools,
@@ -95,9 +96,17 @@ def seeded_store(store):
     return store
 
 
-def _handlers(store, *, registered_tools=None, active=None):
+def _handlers(store, *, registered_tools=None, active=None, local=None):
+    if local is None:
+        import tempfile
+        from pathlib import Path
+
+        from storage.local_skills import LocalSkillStore
+
+        local = LocalSkillStore(db_path=Path(tempfile.mkdtemp()) / "local.sqlite3")
     return skill_tool_handlers(
         store=store,
+        local_store=local,
         get_active_subscriptions=lambda: set(active if active is not None else {"sub-a"}),
         get_registered_tools=(lambda: set(registered_tools or {"tap", "input_text"})),
     )
@@ -260,13 +269,16 @@ def _fastmcp_tool_names(server) -> set[str]:
     )
 
 
-def test_register_skill_catalog_tools_registers_expected_names(seeded_store):
+def test_register_skill_catalog_tools_registers_expected_names(seeded_store, tmp_path):
     from mcp.server.fastmcp import FastMCP
 
+    from storage.local_skills import LocalSkillStore
+
     server = FastMCP("test")
     register_skill_catalog_tools(
         server,
         store=seeded_store,
+        local_store=LocalSkillStore(db_path=tmp_path / "local.sqlite3"),
         get_active_subscriptions=lambda: {"sub-a"},
         get_registered_tools=lambda: {"tap", "input_text"},
     )
@@ -275,14 +287,17 @@ def test_register_skill_catalog_tools_registers_expected_names(seeded_store):
         assert expected in names, f"missing tool: {expected}"
 
 
-def test_no_batch_execute_tool_is_registered(seeded_store):
+def test_no_batch_execute_tool_is_registered(seeded_store, tmp_path):
     """Task 4.4: assert no run_skill_flow / execute / batch tool is registered."""
     from mcp.server.fastmcp import FastMCP
 
+    from storage.local_skills import LocalSkillStore
+
     server = FastMCP("test")
     register_skill_catalog_tools(
         server,
         store=seeded_store,
+        local_store=LocalSkillStore(db_path=tmp_path / "local.sqlite3"),
         get_active_subscriptions=lambda: {"sub-a"},
         get_registered_tools=lambda: {"tap", "input_text"},
     )
@@ -330,3 +345,108 @@ def test_skill_error_hierarchy():
     assert issubclass(SkillNotFoundError, SkillCatalogError)
     assert issubclass(InvalidFlowTemplateError, SkillCatalogError)
     assert issubclass(MissingParameterError, SkillCatalogError)
+    assert issubclass(SkillAuthoringError, SkillCatalogError)
+
+
+# ----------------------------------------------------------------------
+# Authoring tools: create / update / delete with origin dispatch (D10)
+# ----------------------------------------------------------------------
+
+
+@pytest.fixture
+def local(tmp_path):
+    from storage.local_skills import LocalSkillStore
+
+    return LocalSkillStore(db_path=tmp_path / "local.sqlite3")
+
+
+def _authoring_handlers(seeded_store, local):
+    return _handlers(seeded_store, local=local)
+
+
+def test_create_skill_creates_local_skill(seeded_store, local):
+    handlers = _authoring_handlers(seeded_store, local)
+    result = handlers["create_skill"](
+        payload={"kind": "knowledge", "name": "My Note", "content": "hello"}
+    )
+    assert result["ok"] is True
+    assert result["origin"] == "local"
+    new_id = result["skill"]["id"]
+    # discoverable via list with origin local
+    listed = handlers["list_skills"]()
+    entry = next(s for s in listed["skills"] if s["id"] == new_id)
+    assert entry["origin"] == "local"
+    assert entry["locally_overridden"] is False
+
+
+def test_create_skill_rejects_invalid_payload(seeded_store, local):
+    handlers = _authoring_handlers(seeded_store, local)
+    result = handlers["create_skill"](payload={"kind": "knowledge", "name": ""})
+    assert result["ok"] is False
+    assert "authoring" in result["error"]
+
+
+def test_update_skill_edits_local_skill(seeded_store, local):
+    handlers = _authoring_handlers(seeded_store, local)
+    created = handlers["create_skill"](
+        payload={"kind": "knowledge", "name": "Note", "content": "v1"}
+    )
+    local_id = created["skill"]["id"]
+    result = handlers["update_skill"](
+        skill_id=local_id,
+        payload={"kind": "knowledge", "name": "Note", "content": "v2"},
+    )
+    assert result["ok"] is True
+    assert result["origin"] == "local"
+    assert handlers["get_skill"](skill_id=local_id)["skill"]["content"] == "v2"
+
+
+def test_update_skill_on_cloud_id_creates_override(seeded_store, local):
+    handlers = _authoring_handlers(seeded_store, local)
+    # k1 is a cloud knowledge skill in the seeded store
+    result = handlers["update_skill"](
+        skill_id="k1",
+        payload={"kind": "knowledge", "name": "Knowledge One", "content": "OVERRIDDEN"},
+    )
+    assert result["ok"] is True
+    assert result["origin"] == "cloud"
+    assert result["locally_overridden"] is True
+    # get_skill reflects the override
+    got = handlers["get_skill"](skill_id="k1")
+    assert got["skill"]["content"] == "OVERRIDDEN"
+    assert got["skill"]["origin"] == "cloud"
+    assert got["skill"]["locally_overridden"] is True
+
+
+def test_delete_skill_removes_local_skill(seeded_store, local):
+    handlers = _authoring_handlers(seeded_store, local)
+    created = handlers["create_skill"](
+        payload={"kind": "knowledge", "name": "Temp", "content": "x"}
+    )
+    local_id = created["skill"]["id"]
+    result = handlers["delete_skill"](skill_id=local_id)
+    assert result["ok"] is True
+    assert result["origin"] == "local"
+    assert handlers["get_skill"](skill_id=local_id)["ok"] is False
+
+
+def test_delete_skill_on_cloud_override_reverts(seeded_store, local):
+    handlers = _authoring_handlers(seeded_store, local)
+    handlers["update_skill"](
+        skill_id="k1",
+        payload={"kind": "knowledge", "name": "Knowledge One", "content": "OVERRIDDEN"},
+    )
+    result = handlers["delete_skill"](skill_id="k1")
+    assert result["ok"] is True
+    assert result["origin"] == "cloud"
+    # cloud skill resurfaces with original content
+    got = handlers["get_skill"](skill_id="k1")
+    assert got["skill"]["content"] == "body of knowledge"
+    assert got["skill"]["locally_overridden"] is False
+
+
+def test_delete_skill_on_cloud_without_override_errors(seeded_store, local):
+    handlers = _authoring_handlers(seeded_store, local)
+    result = handlers["delete_skill"](skill_id="k1")  # cloud, no override
+    assert result["ok"] is False
+    assert "authoring" in result["error"]