fix: Remove dependency on .auto-build/scripts - auto-create directories

- Commands now use ${CLAUDE_PLUGIN_ROOT}/scripts/ for worktree scripts
- Directory .auto-build-data/ is created automatically when needed
- No manual setup required - plugin is self-contained
- Updated help.md, status.md, worktree.md, spec.md, build.md

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

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

plugin/commands/build.md

@@ -35,7 +35,7 @@ Create an isolated git worktree? (recommended for larger features)
 ```
 
 If yes:
-- Run: `bash .auto-build/scripts/worktree-create.sh {feature-name}`
+- Run: `bash ${CLAUDE_PLUGIN_ROOT}/scripts/worktree-create.sh {feature-name}`
 - Update status.json with worktree path
 - Inform user of worktree location
 
@@ -43,7 +43,7 @@ If yes:
 
 If status is `SPEC_COMPLETE`:
 
-1. Load memory context:
+1. Load memory context (if exists):
    - Read `.auto-build-data/memory/patterns.json`
    - Read `.auto-build-data/memory/gotchas.json`