refactor(scripts): simplify bump.mjs significantly

Drastically simplify the version bump script by removing complex
interactive review features while keeping core functionality.

Changes:
- Removed complex interactive review loop with prompts library (~150 lines)
- Removed advanced changelog refinement loop (~100 lines)
- Removed conditional prompts library loading and fallback logic (~60 lines)
- Removed registry package detection logic (~20 lines)
- Removed duplicate helper functions (~25 lines)
- Kept core version bumping logic
- Kept AI changelog generation with Claude
- Kept simple yes/no/edit review flow
- Kept all git operations (commit, tag, push)
- Kept all command-line flags and options

Benefits:
- Much easier to understand and maintain
- Faster execution
- Still supports AI changelog generation
- Simpler, more predictable behavior

Reduction: 910 lines → 553 lines (-357 lines, 39% smaller)

Author: jdalton