DLPX-97162 Add internal-claude variant for Claude Code developer environments

[prakashsurya]

Problem

Developers working with Claude Code need a pre-configured appliance image that
is ready to use on first boot — with the Claude CLI installed, product repos
pre-cloned, and standard tooling wired up. Today there is no such image; each
developer must manually install and configure everything on a stock internal VM.

Solution

Add a new internal-claude appliance variant (AWS-only) that layers a
claude-internal Ansible role on top of minimal-common + minimal-internal + minimal-development. On first boot the VM provides:

• Claude CLI installed via npm (/usr/local/bin/claude)
• Six product repos pre-cloned under ~delphix/src/ at their configured
  branches, with remote URLs rewritten to SSH form (no build-time token on disk):
  • delphix/dlpx-app-gate @ develop
  • delphix/dlpx-qa-gate @ develop
  • delphix/dms-core-gate @ develop
  • delphix/zfs @ develop
  • delphix/cd-aidlc @ main
  • delphix/git-utils @ main
• support-tools group (gid 4000) with delphix as a member
• NAS mount at /nas via a systemd nas.mount unit
  (After/Wants=network-online.target); uses a unit file rather than
  /etc/fstab because 90-raw-disk-image.binary overwrites fstab after the
  ansible chroot stage
• apt sources modifiable post-boot (cloud-init override in
  /etc/cloud/cloud.cfg.d/99-delphix-claude.cfg)
• git-utils/bin in the login shell PATH via /etc/profile.d/

Also fixes 80-build-configuration.binary to use trap cleanup EXIT so
/proc, /sys, and /dev bind mounts are always torn down even when the
ansible playbook fails mid-run.

The build requires GITHUB_TOKEN to be set (asserted at the top of the role);
without it the build fails fast with a clear message.

Testing Done

• ./gradlew buildInternalClaudeAws succeeds with GITHUB_TOKEN set —
  produces internal-claude-aws.{vmdk,debs.tar.gz,packages.list}
• ./gradlew buildInternalClaudeAws without GITHUB_TOKEN fails fast at the
  assertion task with the expected fail_msg
• git-ab-pre-push -v internal-claude --no-tests passed CI
  (appliance-build pre-push #13984, stage1 #62229)
• Boot-verify checks 4.1–4.10 all passed on a VM cloned from the produced AMI:
  • claude --version → 2.1.132 (Claude Code)
  • All 6 repos present at correct branches with SSH remote URLs
  • support-tools gid 4000, delphix in group
  • nas.mount enabled, unit file correct
  • 99-delphix-claude.cfg present with correct content
  • 61 GB free (> 50 GB)
  • git-utils/bin in PATH
  • No embedded credentials
  • No ~/.claude/settings.json

Future Work

• Ship ~/.claude/settings.json with "Generated with Claude" attribution
  defaults (deferred to a follow-on spec)
• Preload common build dependencies to speed up first use (out of scope)

JIRA: https://perforce.atlassian.net/browse/DLPX-97162