refactor(insights): drop consumer-less get_skill_breakdown alias (simplify-pass)

The 2-line alias had zero production consumers (web_server calls
get_usage_breakdown directly). Tests rewired onto the real API; the
contracts they pin are unchanged. Stale test docstring fixed.

agent/insights.py

@@ -211,9 +211,6 @@ class InsightsEngine:
             "skills": self._compute_skill_breakdown(skill_usage),
         }
 
-    def get_skill_breakdown(self, days: int = 30, source: str = None) -> Dict[str, Any]:
-        return self.get_usage_breakdown(days=days, source=source)["skills"]
-
     # =========================================================================
     # Data gathering (SQL queries)
     # =========================================================================

tests/agent/test_insights.py

@@ -476,7 +476,7 @@ class TestInsightsPopulated:
     def test_get_skill_breakdown_matches_full_generate(self, populated_db):
         engine = InsightsEngine(populated_db)
         full = engine.generate(days=30)
-        focused = engine.get_skill_breakdown(days=30)
+        focused = engine.get_usage_breakdown(days=30)["skills"]
         assert focused == full["skills"]
 
     def test_get_usage_breakdown_matches_full_generate(self, populated_db):
@@ -489,14 +489,14 @@ class TestInsightsPopulated:
     def test_get_skill_breakdown_respects_source_filter(self, populated_db):
         engine = InsightsEngine(populated_db)
         # Only s1 (cli) has skill_view "github-pr-workflow"
-        focused = engine.get_skill_breakdown(days=30, source="cli")
+        focused = engine.get_usage_breakdown(days=30, source="cli")["skills"]
         skill_names = [s["skill"] for s in focused["top_skills"]]
         assert "github-pr-workflow" in skill_names
         # github-code-review was in discord (s4), not cli
         assert "github-code-review" not in skill_names
 
     def test_get_skill_breakdown_empty_db(self, db):
-        focused = InsightsEngine(db).get_skill_breakdown(days=30)
+        focused = InsightsEngine(db).get_usage_breakdown(days=30)["skills"]
         assert focused == {
             "summary": {
                 "total_skill_loads": 0,
@@ -519,7 +519,7 @@ class TestInsightsPopulated:
             tool_calls=[{"function": {"name": "read_file", "arguments": '{"path":"/tmp/x"}'}}],
         )
         db._conn.commit()
-        focused = InsightsEngine(db).get_skill_breakdown(days=30)
+        focused = InsightsEngine(db).get_usage_breakdown(days=30)["skills"]
         assert focused["summary"]["total_skill_actions"] == 0
         assert focused["top_skills"] == []
 

tests/hermes_cli/test_web_server.py

@@ -2223,7 +2223,7 @@ class TestNewEndpoints:
         assert top_skill["last_used_at"] is not None
 
     def test_analytics_usage_skips_full_insights_generate(self):
-        """get_usage_analytics must call get_skill_breakdown, not generate()."""
+        """get_usage_analytics must call get_usage_breakdown, not generate()."""
         from unittest.mock import patch
         from agent.insights import InsightsEngine
         from hermes_state import SessionDB