[Bug] Invalid --output-format causes unhandled ValueError traceback instead of user-friendly error

[Prodesire]

Bug Description

When using --output-format with an invalid value (including case-sensitive mismatches like TEXT instead of text), the CLI crashes with a raw Python traceback instead of displaying a user-friendly error message.

Steps to Reproduce

1. Run iac-code -p "hello" --output-format invalid
2. Or run iac-code -p "hello" --output-format TEXT

Expected Behavior

A clean error message like:

Error: Invalid output format 'invalid'. Valid formats: text, json, stream-json

Actual Behavior

A full Python traceback is displayed:

Traceback (most recent call last):
  File ".../bin/iac-code", line 6, in <module>
    sys.exit(app())
  ...
  File ".../iac_code/cli/main.py", line 191, in main
    fmt = OutputFormat(output_format)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".../enum.py", line 1171, in __new__
    raise ve_exc
ValueError: 'invalid' is not a valid OutputFormat

Root Cause

In src/iac_code/cli/main.py line 191, OutputFormat(output_format) is called without a try/except:

fmt = OutputFormat(output_format)

A fix would be to catch the ValueError and print a friendly message:

try:
    fmt = OutputFormat(output_format)
except ValueError:
    valid = ", ".join(f.value for f in OutputFormat)
    typer.echo(f"Invalid output format '{output_format}'. Valid formats: {valid}", err=True)
    raise typer.Exit(1)

Operating System

macOS

Python Version

3.12.7

iac-code Version

0.2.3

LLM Provider

Alibaba Cloud (DashScope / Qwen)

IaC Type

Not applicable

Additional Context

This also affects case-sensitive inputs — a user typing --output-format JSON gets a crash instead of a helpful hint. Consider normalizing the input with .lower() before validation.

[guima-why]

Fixed in PR #62. Invalid --output-format values now fail with a friendly validation message and no Python traceback, and valid values are handled case-insensitively.

PR: #62

Verified with make translate, make format, make lint, and make test (3777 passed, 244 warnings).

Closing as completed.