Move branch sanitization from contracts to new shared package

Create @t3tools/shared with explicit subpath exports (no barrel) for
shared utility logic. Move sanitizeBranchFragment and
sanitizeFeatureBranchName to @t3tools/shared/git, keeping contracts
focused on schemas.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
dde48e9414Julius Marminge committed on 3/3/2026, 4:46:05 AM· committed by Julius Marmingeparentb1608f4
10 files changedLine totals unavailable