CLI silently ignores unknown flags instead of reporting an error

Bug Description

The Claude Code CLI silently ignores unrecognized command-line flags. Running claude --nonexistent-flag produces no error — it just exits silently. This makes it very difficult to debug issues when a flag is not registered (e.g., behind a feature gate) or misspelled.

Steps to Reproduce

1. Run claude --any-nonexistent-flag
2. Observe: no output, no "unknown option" error

$ claude --totally-fake-flag
$ echo $?
0

Expected Behavior

The CLI should report an error for unrecognized flags, e.g.:

error: unknown option '--totally-fake-flag'

This is the default behavior of most CLI frameworks (including Commander.js) unless explicitly disabled.

Actual Behavior

Silent exit with no output. This is especially problematic when a feature like --teleport is gated behind a feature flag — the user has no way to tell whether the flag is unrecognized vs. failing for another reason.

Environment

• Claude Code version: 2.1.87
• Platform: Linux (ARM aarch64, Tegra)

Impact

This directly contributed to a confusing debugging session where --teleport was silently ignored. The root cause (dirty git tree) was hidden behind a second issue (the flag appearing to not exist) because neither failure produced any output.