feat: add AI markdown reformatting and usage metering to NewsService

Add AI-powered body reformatting for valid articles in the news pipeline, converting raw text walls into clean Markdown with paragraphs, headings, and lists. Introduce `news_usage` database table and `add_news_usage`/`get_news_usage` helpers to track per-cycle gateway costs (calls, tokens, latency, USD) from response headers, reported on the admin Services page. Remove unused `.sidebar-more` CSS and apply `render_title()` to poll question/label fields.

tests/unit/database.py

@@ -185,6 +185,43 @@ def test_build_pagination_metadata():
     assert clamped["total_pages"] == 1
 
 
+def test_news_usage_accumulates_and_computes_averages(local_db):
+    from devplacepy.database import add_news_usage, get_news_usage
+
+    get_table("news_usage").delete()
+    empty = get_news_usage()
+    assert empty["calls"] == 0
+    assert empty["avg_tokens"] == 0.0
+
+    totals = {
+        "calls": 2,
+        "prompt_tokens": 2000,
+        "completion_tokens": 400,
+        "total_tokens": 2400,
+        "cost_usd": 0.0005,
+        "upstream_latency_ms": 1600.0,
+        "total_latency_ms": 1800.0,
+    }
+    add_news_usage(totals)
+    add_news_usage(totals)
+
+    usage = get_news_usage()
+    assert usage["calls"] == 4
+    assert usage["total_tokens"] == 4800
+    assert abs(usage["cost_usd"] - 0.001) < 1e-9
+    assert usage["avg_tokens"] == 1200.0
+    assert usage["avg_cost_usd"] == 0.00025
+    assert usage["avg_tokens_per_second"] == 250.0
+
+
+def test_add_news_usage_ignores_zero_call_batches(local_db):
+    from devplacepy.database import add_news_usage, get_news_usage
+
+    get_table("news_usage").delete()
+    add_news_usage({"calls": 0, "total_tokens": 999, "cost_usd": 1.0})
+    assert get_news_usage()["calls"] == 0
+
+
 def test_interleave_by_author_spreads_consecutive_runs():
     from devplacepy.database import interleave_by_author