Add progress bar to ai_migrator

[shaiananvari8]

/claim #20

Summary

• Adds a dependency-free text progress bar for long �i_migrator.py --source-dir scans.
• Wires progress into directory analysis with a --no-progress escape hatch.
• Fixes the invalid mutating-parameter detector regex so directory analysis can complete.
• Adds ools/validate_ai_migrator_progress.py as a focused smoke validator.

Validation

• python -m py_compile tools/ai_migrator.py tools/validate_ai_migrator_progress.py build.py
• python tools/validate_ai_migrator_progress.py
• git diff --check origin/main...HEAD
• python build.py was run; local module builds fail because the Windows environment is missing the repo's language toolchains. The generated JSON diagnostic is committed, and a matching fallback .logd records the build result because the bundled Windows encryptly tool returned a token but did not write the encrypted file here.

[opirebot]

😅 Ups... the issue does not have any reward yet!