Emdash source with visual editor image upload fix

Fixes:
1. media.ts: wrap placeholder generation in try-catch
2. toolbar.ts: check r.ok, display error message in popover

scripts/query-dumps/cold-only.mjs

@@ -0,0 +1,55 @@
+#!/usr/bin/env node
+/**
+ * Identify queries that fire on cold but not warm in the d1 target —
+ * the cold-isolate startup tax.
+ */
+import { readFileSync, readdirSync } from "node:fs";
+import { dirname, resolve } from "node:path";
+import { fileURLToPath } from "node:url";
+
+const __dirname = dirname(fileURLToPath(import.meta.url));
+const dir = resolve(__dirname, "d1");
+
+function normalize(sql) {
+	return sql.replace(/\s+/g, " ").trim();
+}
+
+const routeOrder = [
+	"root",
+	"posts",
+	"posts_building_for_the_long_term",
+	"pages_about",
+	"category_development",
+	"tag_webdev",
+	"rss_xml",
+	"search",
+];
+
+const coldOnlyAcc = new Map(); // sql -> count
+
+for (const r of routeOrder) {
+	const coldFile = resolve(dir, `${r}.cold.json`);
+	const warmFile = resolve(dir, `${r}.warm.json`);
+	const cold = JSON.parse(readFileSync(coldFile, "utf8"));
+	const warm = JSON.parse(readFileSync(warmFile, "utf8"));
+	const warmSet = new Map();
+	for (const e of warm) warmSet.set(normalize(e.sql), (warmSet.get(normalize(e.sql)) || 0) + 1);
+	for (const e of cold) {
+		const n = normalize(e.sql);
+		const wcount = warmSet.get(n) || 0;
+		if (wcount > 0) {
+			warmSet.set(n, wcount - 1);
+		} else {
+			coldOnlyAcc.set(n, (coldOnlyAcc.get(n) || 0) + 1);
+		}
+	}
+}
+
+const sorted = [...coldOnlyAcc.entries()].sort((a, b) => b[1] - a[1]);
+process.stdout.write(
+	`# Cold-only queries (d1)\n\nQueries that appear in cold-phase dumps but not in matching warm-phase dumps. Aggregated across all routes.\n\n`,
+);
+process.stdout.write(`| count | sql |\n|---:|---|\n`);
+for (const [sql, count] of sorted) {
+	process.stdout.write(`| ${count} | ${sql.slice(0, 200)} |\n`);
+}