Rename /agent-sdk skill to /claude-agent-sdk for clarity

[rysweet]

Problem

The skill is currently named agent-sdk but it's specifically about the Claude Agent SDK, not a generic agent SDK. The name should clearly reflect that it's Claude-specific.

Requirements

Explicit User Requirement (MUST PRESERVE):

• Rename /agent-sdk skill to /claude-agent-sdk skill

Implementation Scope

Directories to Rename (3 locations):

1. .claude/skills/agent-sdk/ → .claude/skills/claude-agent-sdk/
2. docs/claude/skills/agent-sdk/ → docs/claude/skills/claude-agent-sdk/
3. amplifier-bundle/skills/agent-sdk/ → amplifier-bundle/skills/claude-agent-sdk/

Files to Update:

• src/amplihack/known_skills.py - Update skill registry (line 14)
• SKILL.md frontmatter - Change name: agent-sdk to name: claude-agent-sdk
• ~57 files with references to agent-sdk skill

Success Criteria

• All 3 skill directories renamed
• Skill registry updated in src/amplihack/known_skills.py
• Frontmatter name: field updated in SKILL.md
• All file references updated across codebase
• All tests pass with new skill name
• Documentation builds successfully
• Skill invocation works: Skill(skill="claude-agent-sdk")

Acceptance Criteria

• User can invoke /claude-agent-sdk or Skill(skill="claude-agent-sdk")
• Old skill name /agent-sdk no longer works
• CI passes (all tests green)
• No broken links in documentation
• No git grep results for old agent-sdk path references

Notes

• PyPI package dependency claude-agent-sdk is already correct (no change needed)
• Activation keywords remain functional (users can still say "agent sdk" and trigger it)
• Clean break - no deprecation alias (keeps implementation simple)