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/common-hooks.md

@@ -1,35 +0,0 @@
----
-description: "Hook system guidelines and TodoWrite best practices"
-alwaysApply: true
----
-
-# Hooks System
-
-## Hook Types
-
-- **PreToolUse**: Before tool execution (validation, parameter modification)
-- **PostToolUse**: After tool execution (auto-format, checks)
-- **Stop**: When session ends (final verification)
-
-## Auto-Accept Permissions
-
-Use with caution:
-- Enable for trusted, well-defined plans
-- Disable for exploratory work
-- Never use dangerously-skip-permissions flag
-- Configure `allowedTools` in `~/.claude.json` instead
-
-## TodoWrite Best Practices
-
-Use TodoWrite tool to:
-- Track progress on multi-step tasks
-- Verify understanding of instructions
-- Enable real-time steering
-- Show granular implementation steps
-
-Todo list reveals:
-- Out of order steps
-- Missing items
-- Extra unnecessary items
-- Wrong granularity
-- Misinterpreted requirements