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/golang-hooks.md

@@ -1,17 +0,0 @@
----
-description: "Go hooks: gofmt/goimports auto-format, go vet, staticcheck"
-globs: ["**/*.go"]
-alwaysApply: false
----
-
-# Go Hooks
-
-> This file extends [common/hooks.md](../common/hooks.md) with Go specific content.
-
-## PostToolUse Hooks
-
-Configure in `~/.claude/settings.json`:
-
-- **gofmt/goimports**: Auto-format `.go` files after edit
-- **go vet**: Run static analysis after editing `.go` files
-- **staticcheck**: Run extended static checks on modified packages