post: 30 days of agent churn kept 23.5万 of 51.8万 lines (EN + ZH)

The commit-churn post the owner read and approved today, published in the
first-person voice he asked for.

- Voice rewrite before publishing: the draft opened on "when managers or
  recruiters ask how productive an engineer is" and addressed the reader in the
  second person throughout (you/your 12 -> 2, both in the CTA; ZH 你 5 -> 2).
  It now reads as a log entry: "Last week I did something I almost never bother
  to do: I counted my own commits." Headings moved from essay titles to actions.
  Numbers, the 5-repo table and every claim are unchanged.
- Title changed at the owner's request:
  "Why 500,000 Lines of Commit Churn Only Left 230,000 Lines in Production"
  -> "I Committed 518,000 Lines in 30 Days. Production Kept 235,000."
  (ZH: 30 天提交 51.8 万行，生产环境只留下 23.5 万行), pubDate 2026-10-18.
- Fixed two real defects found while making the card: the draft claimed "four
  automated gates" and listed three; and og-gen split titles at the word-count
  midpoint, breaking at "…Lines in / 30 Days" — the splitter now prefers a
  sentence boundary near the middle and falls back to the midpoint.
- og PNG regenerated for the new title, thumbs and banner WebP re-derived.
  Measured: card 2 title lines, overflowY 0, measure_og_banner PASS (tags 1 row,
  banner delta 2), build clean, /posts/ monotonic with this post on top.

Also queued the post at the head of the dev.to drip (queue 69 -> 70).

scripts/og-gen/generate.mjs

@@ -449,11 +449,26 @@ tags = stripped
   .filter(Boolean);
 
 // ---------- build template substitutions ----------
-// split the long title into two balanced lines for readability
+// split the long title into two balanced lines for readability.
+// Prefer a sentence boundary near the middle (". " / "? " / "! " / " — " / ": ") so a
+// line never dangles on a preposition ("…Lines in / 30 Days") when the title states a
+// headline and then a punchline; fall back to the word-count midpoint.
 const words = title.split(' ');
 const mid = Math.ceil(words.length / 2);
-const line1 = words.slice(0, mid).join(' ');
-const line2 = words.slice(mid).join(' ');
+let line1 = words.slice(0, mid).join(' ');
+let line2 = words.slice(mid).join(' ');
+const boundary = /[.?!#—:]\s+/g;
+let best = -1;
+let bm;
+while ((bm = boundary.exec(title)) !== null) {
+  const cut = bm.index + 1; // keep the punctuation on the first line
+  if (cut < title.length * 0.3 || cut > title.length * 0.75) continue;
+  if (best === -1 || Math.abs(cut - title.length / 2) < Math.abs(best - title.length / 2)) best = cut;
+}
+if (best > 0) {
+  line1 = title.slice(0, best).trim();
+  line2 = title.slice(best).trim();
+}
 // escape HTML
 const esc = (s) => s.replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;');
 // title size: short titles can be larger