feat(ecc): prune plugin 43→12 items, promote 7 rules to .claude/rules/ (#245)

ECC community plugin pruning: removed 530+ non-essential files
(.cursor/, .opencode/, docs/ja-JP, docs/zh-CN, docs/zh-TW,
language-specific skills/agents/rules). Retained 4 agents,
3 commands, 5 skills. Promoted 13 rule files (8 common + 5
typescript) to .claude/rules/ for CC native loading. Extracted
reusable patterns to EXTRACTED-PATTERNS.md.

.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)