Bun 1.4.2 everywhere CI and setup pin the tested version

Bun 1.4.0 on Windows aborts about 3% of free-suite shards with native
bad-handle errors (main too; #3037); the same head on 1.4.2 had none in 180
shard runs. Every current 1.4.0 pin moves together, as bun-version-drift
requires: setup-bun in every workflow (CSO orchestration included), the eval
image (sha256 from bun-v1.4.2's SHASUMS256.txt, re-hashed locally), GitLab,
the Ubicloud free-suite setup, gstack-bun-version.sh's tested version,
engines.bun and @types/bun, the install hint in generated skills, the Dia and
cookie native-qualification pins, and docs and tests that state the current
pin. Recorded 1.4.0 observations, fixtures, CHANGELOG history and the CSO
images' oven/bun:1.3.10 base stay.

scripts/resolvers/browse.ts

@@ -133,7 +133,7 @@ If \`NEEDS_SETUP\`:
 3. If \`bun\` is not installed:
    \`\`\`bash
    if ! command -v bun >/dev/null 2>&1; then
-     BUN_VERSION="1.4.0"
+     BUN_VERSION="1.4.2"
      BUN_INSTALL_SHA="bab8acfb046aac8c72407bdcce903957665d655d7acaa3e11c7c4616beae68dd"
      tmpfile=$(mktemp "\${TMPDIR:-/tmp}/bun-install.XXXXXX")
      curl -fsSL "https://bun.sh/install" -o "$tmpfile"

scripts/ubicloud/setup-free-suite.sh

@@ -4,7 +4,7 @@
 # Runs as user `ubi` (passwordless sudo) from the synced checkout.
 set -euo pipefail
 
-BUN_VERSION=1.4.0
+BUN_VERSION=1.4.2
 NODE_VERSION=22.20.0
 
 export DEBIAN_FRONTEND=noninteractive