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/relink-bins-if-needed.mjs

@@ -0,0 +1,24 @@
+#!/usr/bin/env node
+// Relink workspace bin symlinks after build, but only when needed.
+// pnpm only creates bin links when the target file exists at install time.
+// Since the CLI lives in dist/, it doesn't exist until after the first build.
+
+import { execSync } from "node:child_process";
+import { existsSync } from "node:fs";
+
+// Skip in CI — bins are handled by the CI setup step
+if (process.env.CI) process.exit(0);
+
+const CLI_SRC = "packages/core/dist/cli/index.mjs";
+
+// If the built CLI doesn't exist, the build itself failed — nothing to relink
+if (!existsSync(CLI_SRC)) process.exit(0);
+
+const binDir = execSync("pnpm bin", { encoding: "utf-8" }).trim();
+const cliBin = `${binDir}/emdash`;
+
+// If the bin symlink is missing or broken, relink
+if (!existsSync(cliBin)) {
+	console.log("CLI bin missing — relinking...");
+	execSync("pnpm install --frozen-lockfile", { stdio: "inherit" });
+}