fix: pin the claude CLI to an exact version in the CI image + tripwire

The image installed @anthropic-ai/claude-code UNPINNED and rebuilt weekly
'to pick up CLI updates' — while bun sat carefully pinned at 1.3.13 two RUN
lines above. The PTY harness screen-scrapes this CLI's TUI, and that drift
broke it three separate times (welcome-screen wedge on 2.1.233, skillify
HOME discovery on 2.1.237, guard/freeze hooks on 2.1.162), each debugged as
a flake first. Pin 2.1.251 (current latest), bump deliberately via a PR
that runs the PTY gate, and enforce with test/ci-image-cli-pin.test.ts:
any global npm install in Dockerfile.ci without an exact @X.Y.Z pin fails
the free suite. The weekly ci-image cron stays as a cheap tag self-heal.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.github/docker/Dockerfile.ci

@@ -74,8 +74,15 @@ ENV BUN_INSTALL="/usr/local"
 RUN curl --retry 5 --retry-delay 5 --retry-connrefused -fsSL https://bun.sh/install \
     | bash -s "bun-v1.3.13"
 
-# Claude CLI
-RUN npm i -g @anthropic-ai/claude-code
+# Claude CLI — pinned to an EXACT version, same discipline as the bun pin
+# above. The PTY harness (test/helpers/claude-pty-runner.ts) screen-scrapes
+# this CLI's TUI (trust dialog, input prompt, spinner glyphs); an unpinned
+# install rebuilt weekly rode the TUI wherever it drifted, and that drift
+# broke the harness three separate times (welcome-screen wedge on 2.1.233,
+# skillify HOME discovery on 2.1.237, guard/freeze hooks on 2.1.162).
+# Bump deliberately, via a PR that runs the PTY gate against the new TUI.
+# test/ci-image-cli-pin.test.ts fails the free suite if this pin is removed.
+RUN npm i -g @anthropic-ai/claude-code@2.1.251
 
 # Playwright system deps (Chromium) — needed for browse E2E tests
 RUN npx playwright install-deps chromium

.github/workflows/ci-image.yml

@@ -1,8 +1,12 @@
 name: Build CI Image
 on:
-  # Rebuild weekly (Monday 4am UTC) to pick up CLI updates — deliberately 2h
-  # BEFORE evals-periodic's 6am cron so the weekly eval run finds a fresh
-  # image instead of racing a half-pushed tag or duplicating the build.
+  # Weekly self-heal (Monday 4am UTC) — deliberately 2h BEFORE
+  # evals-periodic's 6am cron so the weekly eval run finds the image instead
+  # of racing a half-pushed tag. With the claude CLI pinned in Dockerfile.ci
+  # (v1.76+), this cron no longer pulls CLI updates: when the content-hash
+  # tag already exists it's a ~30s no-op, and it only rebuilds if the tag
+  # was somehow lost. CLI bumps happen by editing the Dockerfile pin in a PR
+  # that runs the PTY gate against the new TUI.
   schedule:
     - cron: '0 4 * * 1'
   # Rebuild on Dockerfile or lockfile changes. package.json is deliberately

test/ci-image-cli-pin.test.ts

@@ -0,0 +1,67 @@
+/**
+ * Provider CLIs baked into the CI image must be pinned to EXACT versions.
+ *
+ * The PTY harness (test/helpers/claude-pty-runner.ts) screen-scrapes the
+ * claude CLI's TUI — trust dialog, input-prompt ready marker, spinner glyphs.
+ * The image used to install `npm i -g @anthropic-ai/claude-code` UNPINNED and
+ * rebuild weekly "to pick up CLI updates", while bun sat carefully pinned at
+ * 1.3.13 two RUN lines above — the exact drift class the bun pin exists for.
+ * Receipts: TUI drift broke the harness three separate times (welcome-screen
+ * wedge vs CLI 2.1.233, skillify HOME discovery on 2.1.237, guard/freeze
+ * hooks on 2.1.162), each debugged as a "flake" before being traced to an
+ * unpinned weekly-latest CLI.
+ *
+ * This tripwire fails the free suite when any globally-installed npm package
+ * in Dockerfile.ci lacks an exact `@X.Y.Z` pin. Bumps are deliberate: edit
+ * the pin in a PR and run the PTY gate against the new TUI before merging.
+ */
+import { describe, expect, test } from 'bun:test';
+import * as fs from 'node:fs';
+import * as path from 'node:path';
+
+const ROOT = path.resolve(__dirname, '..');
+const DOCKERFILE = path.join(ROOT, '.github', 'docker', 'Dockerfile.ci');
+
+/** Package specs from every `npm i -g` / `npm install -g` in the Dockerfile. */
+export function globalNpmInstallSpecs(source: string): string[] {
+  const specs: string[] = [];
+  for (const match of source.matchAll(/npm\s+(?:i|install)\s+(?:-g|--global)\s+([^\n\\&|;]+)/g)) {
+    for (const spec of match[1].trim().split(/\s+/)) {
+      if (spec.startsWith('-')) continue; // flags like --no-fund
+      specs.push(spec);
+    }
+  }
+  return specs;
+}
+
+/** Exact pin = a trailing @<semver> with no range operator (no ^ ~ x *). */
+export function isExactlyPinned(spec: string): boolean {
+  // Scoped (@scope/name@1.2.3) or bare (name@1.2.3); version must be exact.
+  const at = spec.lastIndexOf('@');
+  if (at <= 0) return false; // no version at all (or a bare scope)
+  const version = spec.slice(at + 1);
+  return /^\d+\.\d+\.\d+(?:-[\w.]+)?$/.test(version);
+}
+
+describe('ci image provider-CLI pins', () => {
+  const source = fs.readFileSync(DOCKERFILE, 'utf-8');
+  const specs = globalNpmInstallSpecs(source);
+
+  test('the image installs at least the claude CLI globally (scan must not rot)', () => {
+    expect(
+      specs.some((s) => s.startsWith('@anthropic-ai/claude-code@')),
+      `expected a pinned @anthropic-ai/claude-code install in ${path.relative(ROOT, DOCKERFILE)}; found: ${specs.join(', ') || '(none)'}`,
+    ).toBe(true);
+  });
+
+  test('every global npm install carries an exact @X.Y.Z pin', () => {
+    const unpinned = specs.filter((s) => !isExactlyPinned(s));
+    expect(
+      unpinned,
+      `unpinned global npm installs in Dockerfile.ci: ${unpinned.join(', ')}\n`
+      + 'Pin the exact version (name@X.Y.Z) and bump via a PR that runs the '
+      + 'PTY gate against the new TUI — weekly-latest CLI drift broke the '
+      + 'harness three times before this tripwire existed.',
+    ).toHaveLength(0);
+  });
+});