feat(v2.3.0): Add multi-agent installation support

Add automatic skill installation to 10+ AI coding agents with a single command.

New Features:
- New install-agent command for installing skills to any AI agent
- Support for 10+ agents: Claude Code, Cursor, VS Code, Amp, Goose, OpenCode, Letta, Aide, Windsurf
- Smart path resolution (global ~/.agent vs project-relative .agent/)
- Fuzzy agent name matching with suggestions
- --agent all flag to install to all agents at once
- --force flag to overwrite existing installations
- --dry-run flag to preview installations
- Comprehensive error handling and user feedback

Implementation:
- Created install_agent.py (379 lines) with core installation logic
- Updated main.py with install-agent subcommand
- Updated pyproject.toml with entry point
- Added 32 comprehensive tests (all passing, 603 total)
- No regressions in existing functionality

Documentation:
- Updated README.md with multi-agent installation guide
- Updated CLAUDE.md with install-agent examples
- Updated CHANGELOG.md with v2.3.0 release notes
- Added agent compatibility table

Technical Details:
- 100% own implementation (no external dependencies)
- Pure Python using stdlib (shutil, pathlib, argparse)
- Compatible with Agent Skills open standard (agentskills.io)
- Works offline

Closes #210

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src/skill_seekers/cli/main.py

@@ -8,20 +8,22 @@ Usage:
     skill-seekers <command> [options]
 
 Commands:
-    scrape      Scrape documentation website
-    github      Scrape GitHub repository
-    pdf         Extract from PDF file
-    unified     Multi-source scraping (docs + GitHub + PDF)
-    enhance     AI-powered enhancement (local, no API key)
-    package     Package skill into .zip file
-    upload      Upload skill to Claude
-    estimate    Estimate page count before scraping
+    scrape        Scrape documentation website
+    github        Scrape GitHub repository
+    pdf           Extract from PDF file
+    unified       Multi-source scraping (docs + GitHub + PDF)
+    enhance       AI-powered enhancement (local, no API key)
+    package       Package skill into .zip file
+    upload        Upload skill to Claude
+    estimate      Estimate page count before scraping
+    install-agent Install skill to AI agent directories
 
 Examples:
     skill-seekers scrape --config configs/react.json
     skill-seekers github --repo microsoft/TypeScript
     skill-seekers unified --config configs/react_unified.json
     skill-seekers package output/react/
+    skill-seekers install-agent output/react/ --agent cursor
 """
 
 import sys
@@ -60,7 +62,7 @@ For more information: https://github.com/yusufkaraaslan/Skill_Seekers
     parser.add_argument(
         "--version",
         action="version",
-        version="%(prog)s 2.2.0"
+        version="%(prog)s 2.3.0"
     )
 
     subparsers = parser.add_subparsers(
@@ -156,6 +158,32 @@ For more information: https://github.com/yusufkaraaslan/Skill_Seekers
     estimate_parser.add_argument("config", help="Config JSON file")
     estimate_parser.add_argument("--max-discovery", type=int, help="Max pages to discover")
 
+    # === install-agent subcommand ===
+    install_agent_parser = subparsers.add_parser(
+        "install-agent",
+        help="Install skill to AI agent directories",
+        description="Copy skill to agent-specific installation directories"
+    )
+    install_agent_parser.add_argument(
+        "skill_directory",
+        help="Skill directory path (e.g., output/react/)"
+    )
+    install_agent_parser.add_argument(
+        "--agent",
+        required=True,
+        help="Agent name (claude, cursor, vscode, amp, goose, opencode, all)"
+    )
+    install_agent_parser.add_argument(
+        "--force",
+        action="store_true",
+        help="Overwrite existing installation without asking"
+    )
+    install_agent_parser.add_argument(
+        "--dry-run",
+        action="store_true",
+        help="Preview installation without making changes"
+    )
+
     # === install subcommand ===
     install_parser = subparsers.add_parser(
         "install",
@@ -300,6 +328,15 @@ def main(argv: Optional[List[str]] = None) -> int:
                 sys.argv.extend(["--max-discovery", str(args.max_discovery)])
             return estimate_main() or 0
 
+        elif args.command == "install-agent":
+            from skill_seekers.cli.install_agent import main as install_agent_main
+            sys.argv = ["install_agent.py", args.skill_directory, "--agent", args.agent]
+            if args.force:
+                sys.argv.append("--force")
+            if args.dry_run:
+                sys.argv.append("--dry-run")
+            return install_agent_main() or 0
+
         elif args.command == "install":
             from skill_seekers.cli.install_skill import main as install_main
             sys.argv = ["install_skill.py"]