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.

rules/golang/coding-style.md

@@ -1,32 +0,0 @@
----
-paths:
-  - "**/*.go"
-  - "**/go.mod"
-  - "**/go.sum"
----
-# Go Coding Style
-
-> This file extends [common/coding-style.md](../common/coding-style.md) with Go specific content.
-
-## Formatting
-
-- **gofmt** and **goimports** are mandatory — no style debates
-
-## Design Principles
-
-- Accept interfaces, return structs
-- Keep interfaces small (1-3 methods)
-
-## Error Handling
-
-Always wrap errors with context:
-
-```go
-if err != nil {
-    return fmt.Errorf("failed to create user: %w", err)
-}
-```
-
-## Reference
-
-See skill: `golang-patterns` for comprehensive Go idioms and patterns.

rules/golang/hooks.md

@@ -1,17 +0,0 @@
----
-paths:
-  - "**/*.go"
-  - "**/go.mod"
-  - "**/go.sum"
----
-# 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

rules/golang/patterns.md

@@ -1,45 +0,0 @@
----
-paths:
-  - "**/*.go"
-  - "**/go.mod"
-  - "**/go.sum"
----
-# Go Patterns
-
-> This file extends [common/patterns.md](../common/patterns.md) with Go specific content.
-
-## Functional Options
-
-```go
-type Option func(*Server)
-
-func WithPort(port int) Option {
-    return func(s *Server) { s.port = port }
-}
-
-func NewServer(opts ...Option) *Server {
-    s := &Server{port: 8080}
-    for _, opt := range opts {
-        opt(s)
-    }
-    return s
-}
-```
-
-## Small Interfaces
-
-Define interfaces where they are used, not where they are implemented.
-
-## Dependency Injection
-
-Use constructor functions to inject dependencies:
-
-```go
-func NewUserService(repo UserRepository, logger Logger) *UserService {
-    return &UserService{repo: repo, logger: logger}
-}
-```
-
-## Reference
-
-See skill: `golang-patterns` for comprehensive Go patterns including concurrency, error handling, and package organization.

rules/golang/security.md

@@ -1,34 +0,0 @@
----
-paths:
-  - "**/*.go"
-  - "**/go.mod"
-  - "**/go.sum"
----
-# Go Security
-
-> This file extends [common/security.md](../common/security.md) with Go specific content.
-
-## Secret Management
-
-```go
-apiKey := os.Getenv("OPENAI_API_KEY")
-if apiKey == "" {
-    log.Fatal("OPENAI_API_KEY not configured")
-}
-```
-
-## Security Scanning
-
-- Use **gosec** for static security analysis:
-  ```bash
-  gosec ./...
-  ```
-
-## Context & Timeouts
-
-Always use `context.Context` for timeout control:
-
-```go
-ctx, cancel := context.WithTimeout(ctx, 5*time.Second)
-defer cancel()
-```

rules/golang/testing.md

@@ -1,31 +0,0 @@
----
-paths:
-  - "**/*.go"
-  - "**/go.mod"
-  - "**/go.sum"
----
-# Go Testing
-
-> This file extends [common/testing.md](../common/testing.md) with Go specific content.
-
-## Framework
-
-Use the standard `go test` with **table-driven tests**.
-
-## Race Detection
-
-Always run with the `-race` flag:
-
-```bash
-go test -race ./...
-```
-
-## Coverage
-
-```bash
-go test -cover ./...
-```
-
-## Reference
-
-See skill: `golang-testing` for detailed Go testing patterns and helpers.