fix(claude-code): propagate installation failures

[Edd88-pixel]

Why

Claude Code installation failures could be logged while the module continued and reported success. The skip-install path could also complete without a usable pre-installed binary, leaving a workspace apparently configured while Claude Code was unavailable.

Changes

• download the official installer to a temporary file with bounded retries and timeouts before execution
• validate the installer syntax, propagate download and installation failures, and verify the installed binary
• require a usable pre-installed binary when installation is disabled and expose its resolved path to later configuration steps
• cover installation, binary validation, authentication, MCP, telemetry, and provider scenarios with deterministic module tests
• bump the module patch version to 5.4.1

Validation

• E2E container tests completed successfully: bun test main.test.ts — 26 passed, 0 failed (196 assertions)
• Terraform tests: terraform test — 27 passed, 0 failed
• Terraform configuration: terraform validate — passed
• TypeScript: bun x tsc --noEmit — passed
• Formatting: targeted Prettier checks and terraform fmt -check — passed
• Shell: ShellCheck on the rendered installer template — passed