Add composable issue validators to internal/validation package:
- IssueValidator type with Chain() composition function
- Exists(), NotTemplate(), NotPinned(), NotClosed(), NotHooked() validators
- HasStatus(), HasType() for checking allowed values
- ForUpdate(), ForClose(), ForDelete(), ForReopen() convenience chains
Update cmd/bd/show_unit_helpers.go to use centralized validators instead
of duplicated inline validation logic. This enables consistent validation
across all commands with a single source of truth.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Analysis found these commands are dead code:
- gt never calls `bd pin` - uses `bd update --status=pinned` instead
- Beads.Pin() wrapper exists but is never called
- bd hook functionality duplicated by gt mol status
- Code comment says "pinned field is cosmetic for bd hook visibility"
Removed:
- cmd/bd/pin.go
- cmd/bd/unpin.go
- cmd/bd/hook.go
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
