address review: remove .cursor/ duplicate, use is not None checks

Changes based on CodeRabbit review feedback:

1. Remove entire .cursor/ directory — it was an identical copy of the
   main skills/commands/agents/rules, causing maintenance drift.
   Users of Cursor can reference the canonical files directly.

2. Use explicit `is not None` checks instead of truthiness for
   parsed['input'] and parsed['output']. Empty strings or empty
   dicts are valid values that should be preserved.

.cursor/rules/python-hooks.md

@@ -1,20 +0,0 @@
----
-description: "Python hooks: black/ruff auto-format, mypy/pyright type checking, print() warnings"
-globs: ["**/*.py"]
-alwaysApply: false
----
-
-# Python Hooks
-
-> This file extends [common/hooks.md](../common/hooks.md) with Python specific content.
-
-## PostToolUse Hooks
-
-Configure in `~/.claude/settings.json`:
-
-- **black/ruff**: Auto-format `.py` files after edit
-- **mypy/pyright**: Run type checking after editing `.py` files
-
-## Warnings
-
-- Warn about `print()` statements in edited files (use `logging` module instead)