Add Progress Indicators for Long Operations

[jtdub]

Problem

When processing large configuration files, there is no feedback to the user that the tool is working. This can make it seem like the tool is hung.

Proposed Solution

Add progress indicators using Click's built-in progress features or simple spinners:

• Show progress only when stderr is a TTY
• Suppress with --quiet or -q flag
• Always show on -v verbose mode

Acceptance Criteria

• Progress indicator shown during processing
• Indicator hidden when output is piped
• --quiet flag suppresses all non-error output
• Works correctly with --output file flag