feat: context-anchored version bump with comprehensive test suite

Redesigned version bump from bare regex to context-anchored substitution.
Every replacement is proven SynapseML-related by surrounding text —
safe for fully unattended automated releases.

Features:
- 20 context patterns (self/line/file-anchored)
- Auto-detects current version from docusaurus.config.js
- Enforces X.Y.Z format, version must increase
- Two-pass: read all → validate → write all
- Post-condition self-verification (re-reads files after write)
- Broad sweep warns about old version in unscanned files
- Runs docusaurus docs:version when website/docs/ exists
- 175 tests: unit, integration, fuzz, adversarial, round-trip,
  snapshot regression, and 10 historical bump replays

Usage: python scripts/bump-version.py --to 1.1.3 [--dry-run]

Co-authored-by: smamindl <106691906+smamindl@users.noreply.github.com>

Author: BrendanWalsh