chore(web/scripts): migration runner using @neondatabase/serverless

Single-file Node script that loads NEON_DATABASE_URL via
`node --env-file=.env.local`, splits a drizzle migration on the
`--> statement-breakpoint` marker, and runs each statement over
the existing HTTP driver.

Useful because:

  - psql isn't always installed on dev machines (this came up
    when shipping migration 0022).
  - .claude/rules/db-migrations.md mandates manual application
    against prod — this script is the manual path without
    requiring brew/libpq.
  - The same driver the runtime uses, so behavior is consistent
    with what production would see.

Usage:

  node --env-file=.env.local scripts/run-migration.mjs \\
    src/db/migrations/0022_ai_tagging.sql

Reports per-statement OK/FAIL and bails on first error. Does not
write to a migrations journal — drizzle-kit owns _journal.json,
this is just for the apply step.

Author: xiaolai

web/scripts/run-migration.mjs

@@ -0,0 +1,50 @@
+// One-shot migration runner via @neondatabase/serverless HTTP driver.
+// Usage: node --env-file=.env.local scripts/run-migration.mjs <path>
+//
+// Splits on drizzle's `--> statement-breakpoint` marker and runs
+// each statement separately. Reports which already-applied
+// statements no-op'd vs which actually ran.
+
+import { neon } from "@neondatabase/serverless";
+import { readFileSync } from "node:fs";
+
+const url = process.env.NEON_DATABASE_URL;
+if (!url) {
+  console.error("NEON_DATABASE_URL missing");
+  process.exit(1);
+}
+
+const path = process.argv[2];
+if (!path) {
+  console.error("usage: run-migration.mjs <path-to-sql>");
+  process.exit(1);
+}
+
+const sql = neon(url);
+
+// Identify which DB we're hitting before changing anything.
+const [{ host_db }] = await sql`SELECT current_database() AS host_db`;
+console.log(`Target DB: ${host_db}`);
+
+const file = readFileSync(path, "utf8");
+const statements = file
+  .split("--> statement-breakpoint")
+  .map((s) => s.replace(/^\s*--.*$/gm, "").trim())
+  .filter((s) => s.length > 0);
+
+console.log(`Running ${statements.length} statements from ${path}...`);
+
+for (let i = 0; i < statements.length; i++) {
+  const stmt = statements[i];
+  const head = stmt.split("\n")[0].slice(0, 80);
+  try {
+    await sql.query(stmt);
+    console.log(`  [${i + 1}/${statements.length}] OK   ${head}`);
+  } catch (err) {
+    console.error(`  [${i + 1}/${statements.length}] FAIL ${head}`);
+    console.error(`         ${err.message}`);
+    process.exit(1);
+  }
+}
+
+console.log("Migration applied.");