refactor: remove unused bd pin/unpin/hook commands (bd-x0zl)

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>

integrations/beads-mcp/src/beads_mcp/models.py

@@ -209,6 +209,13 @@ class ReadyWorkParams(BaseModel):
     labels_any: list[str] | None = None  # OR: must have at least one
     unassigned: bool = False  # Filter to only unassigned issues
     sort_policy: str | None = None  # hybrid, priority, oldest
+    parent_id: str | None = None  # Filter to descendants of this bead/epic
+
+
+class BlockedParams(BaseModel):
+    """Parameters for querying blocked issues."""
+
+    parent_id: str | None = None  # Filter to descendants of this bead/epic
 
 
 class ListIssuesParams(BaseModel):