feat: add Perl language rules and update documentation

Add rules/perl/ with 5 rule files (coding-style, testing, patterns,
  hooks, security) following the same structure as existing languages.
  Update README.md, README.zh-CN.md, and rules/README.md to document
  Perl support including badges, directory trees, install instructions,
  and rule counts.

rules/perl/patterns.md

@@ -0,0 +1,76 @@
+---
+paths:
+  - "**/*.pl"
+  - "**/*.pm"
+  - "**/*.t"
+  - "**/*.psgi"
+  - "**/*.cgi"
+---
+# Perl Patterns
+
+> This file extends [common/patterns.md](../common/patterns.md) with Perl specific content.
+
+## Repository Pattern
+
+Use **DBI** or **DBIx::Class** behind an interface:
+
+```perl
+package MyApp::Repo::User;
+use Moo;
+
+has dbh => (is => 'ro', required => 1);
+
+sub find_by_id ($self, $id) {
+    my $sth = $self->dbh->prepare('SELECT * FROM users WHERE id = ?');
+    $sth->execute($id);
+    return $sth->fetchrow_hashref;
+}
+```
+
+## DTOs / Value Objects
+
+Use **Moo** classes with **Types::Standard** (equivalent to Python dataclasses):
+
+```perl
+package MyApp::DTO::User;
+use Moo;
+use Types::Standard qw(Str Int);
+
+has name  => (is => 'ro', isa => Str, required => 1);
+has email => (is => 'ro', isa => Str, required => 1);
+has age   => (is => 'ro', isa => Int);
+```
+
+## Resource Management
+
+- Always use **three-arg open** with `autodie`
+- Use **Path::Tiny** for file operations
+
+```perl
+use autodie;
+use Path::Tiny;
+
+my $content = path('config.json')->slurp_utf8;
+```
+
+## Module Interface
+
+Use `Exporter 'import'` with `@EXPORT_OK` — never `@EXPORT`:
+
+```perl
+use Exporter 'import';
+our @EXPORT_OK = qw(parse_config validate_input);
+```
+
+## Dependency Management
+
+Use **cpanfile** + **carton** for reproducible installs:
+
+```bash
+carton install
+carton exec prove -lr t/
+```
+
+## Reference
+
+See skill: `perl-patterns` for comprehensive modern Perl patterns and idioms.