fix(db): sweep positional jsonb double-encode sites + AST CI guard (#2324)

Every executeRaw/.unsafe site that bound JSON.stringify(x) to a bare positional
jsonb cast double-encodes on real Postgres (same class as #2339). Sweep them all
to the text::jsonb form across query-cache, sources-ops, llm-base,
calibration-profile, impact-capture, subagent, receipt-write, traversal-cache,
symbol-resolver, and the agent/sources commands. Adds scripts/check-jsonb-params.mjs
(AST-lite scanner for the positional form the legacy template grep misses, incl.
generic-typed calls), wired into check-jsonb-pattern.sh, with a self-test. PGLite's
native db.query is not scanned — it parses text to jsonb natively, so the bug can't
occur there.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

test/check-jsonb-params.test.ts

@@ -0,0 +1,83 @@
+/**
+ * Self-test for scripts/check-jsonb-params.mjs — the positional jsonb
+ * double-encode guard (#2339 / #2324 class). Verifies it catches the bug shape
+ * (including generic-typed calls and the `jsonStr` variable case is acknowledged
+ * as out of scope) and does NOT false-positive on the sanctioned forms.
+ *
+ * Fixtures are written to a temp dir and the scanner is pointed at it via argv,
+ * so this never touches the real src/ tree.
+ */
+import { describe, test, expect, beforeAll, afterAll } from 'bun:test';
+import { mkdtempSync, writeFileSync, mkdirSync, rmSync } from 'node:fs';
+import { join } from 'node:path';
+import { tmpdir } from 'node:os';
+
+const SCRIPT = join(import.meta.dir, '..', 'scripts', 'check-jsonb-params.mjs');
+
+let root: string;
+let badDir: string;
+let goodDir: string;
+
+function runGuard(dir: string): { code: number; err: string } {
+  const res = Bun.spawnSync([process.execPath, SCRIPT, dir]);
+  return { code: res.exitCode, err: res.stderr.toString() + res.stdout.toString() };
+}
+
+beforeAll(() => {
+  root = mkdtempSync(join(tmpdir(), 'jsonb-guard-'));
+  badDir = join(root, 'bad');
+  goodDir = join(root, 'good');
+  mkdirSync(badDir, { recursive: true });
+  mkdirSync(goodDir, { recursive: true });
+
+  // BAD: positional $1::jsonb bound to a JSON.stringify'd value.
+  writeFileSync(
+    join(badDir, 'bad.ts'),
+    "await engine.executeRaw(`INSERT INTO t (a) VALUES ($1::jsonb)`, [JSON.stringify(x)]);\n",
+  );
+  // BAD: generic-typed executeRaw<T>(...) must still be caught.
+  writeFileSync(
+    join(badDir, 'bad_generic.ts'),
+    "await engine.executeRaw<{ id: string }>(`UPDATE t SET a = $2::jsonb WHERE id = $1`, [id, JSON.stringify(x)]);\n",
+  );
+
+  // GOOD: the fix — $1::text::jsonb.
+  writeFileSync(
+    join(goodDir, 'good_text.ts'),
+    "await engine.executeRaw(`INSERT INTO t (a) VALUES ($1::text::jsonb)`, [JSON.stringify(x)]);\n",
+  );
+  // GOOD: text[] array path (the appendCompleted unnest shape).
+  writeFileSync(
+    join(goodDir, 'good_array.ts'),
+    "await engine.executeRaw(`INSERT INTO t (a) SELECT unnest($1::text[])`, [JSON.stringify(arr)]);\n",
+  );
+  // GOOD: executeRawJsonb passes a raw object, not a string — excluded.
+  writeFileSync(
+    join(goodDir, 'good_helper.ts'),
+    "await executeRawJsonb(engine, `INSERT INTO t (a) VALUES ($1::jsonb)`, [], [JSON.stringify(x)]);\n",
+  );
+  // GOOD: explicit opt-out for a rare legitimate object-binding case.
+  writeFileSync(
+    join(goodDir, 'good_optout.ts'),
+    "await engine.executeRaw(`INSERT INTO t (a) VALUES ($1::jsonb)` /* jsonb-guard-ok */, [JSON.stringify(x)]);\n",
+  );
+});
+
+afterAll(() => {
+  rmSync(root, { recursive: true, force: true });
+});
+
+describe('check-jsonb-params guard', () => {
+  test('flags positional $N::jsonb + JSON.stringify (incl. generic-typed calls)', () => {
+    const { code, err } = runGuard(badDir);
+    expect(code).toBe(1);
+    expect(err).toContain('bad.ts');
+    expect(err).toContain('bad_generic.ts');
+  });
+
+  test('passes the sanctioned forms (::text::jsonb, ::text[], executeRawJsonb, opt-out)', () => {
+    const { code, err } = runGuard(goodDir);
+    expect(code).toBe(0);
+    expect(err).toContain('clean');
+  });
+});