fix: preserve full-width Windows filesystem IDs

[douglasmonsky]

Summary

• preserve complete Windows filesystem device/inode identifiers as versioned fsid-v1: text before SQLite binding
• normalize legacy integer source rows so existing checkpoints remain valid without a forced full reparse
• fall back safely on malformed identities and add synthetic 128-bit regression coverage

Root cause

Python 3.12+ on Windows may expose a 128-bit stat().st_ino. Binding that arbitrary-precision Python integer to SQLite INTEGER raises OverflowError because SQLite integers are signed 64-bit.

Validation

• Ruff, mypy, and compileall
• 1,016 tests passed
• coverage suite passed at 88%
• 24 dashboard JavaScript syntax checks
• release and distribution checks
• wheel/sdist build and Twine checks
• installed-package smoke test

Addresses #278. The issue will remain open until the reporter confirms the fix on Windows.