Rename ralph-wiggum plugin to ralph-loop per legal guidance (#142)

- Rename plugin from "ralph-wiggum" to "ralph-loop" to avoid trademark concerns
- Update all internal references to use "Ralph Loop" as the prominent name
- Keep explanatory text noting it "implements the Ralph Wiggum technique" (allowed)
- Rename plugin directory from plugins/ralph-wiggum to plugins/ralph-loop
- Update marketplace.json with new plugin name and source path
- Update plugin-dev documentation references

This change follows legal's recommendation to replace "Wiggum" with "Loop"
in the plugin name while still explaining the technique origin.

Slack thread: https://anthropic.slack.com/archives/C09KU300P7F/p1767741142753959

Co-authored-by: Claude <noreply@anthropic.com>

plugins/ralph-loop/README.md

@@ -0,0 +1,179 @@
+# Ralph Loop Plugin
+
+Implementation of the Ralph Wiggum technique for iterative, self-referential AI development loops in Claude Code.
+
+## What is Ralph Loop?
+
+Ralph Loop is a development methodology based on continuous AI agent loops. As Geoffrey Huntley describes it: **"Ralph is a Bash loop"** - a simple `while true` that repeatedly feeds an AI agent a prompt file, allowing it to iteratively improve its work until completion.
+
+This technique is inspired by the Ralph Wiggum coding technique (named after the character from The Simpsons), embodying the philosophy of persistent iteration despite setbacks.
+
+### Core Concept
+
+This plugin implements Ralph using a **Stop hook** that intercepts Claude's exit attempts:
+
+```bash
+# You run ONCE:
+/ralph-loop "Your task description" --completion-promise "DONE"
+
+# Then Claude Code automatically:
+# 1. Works on the task
+# 2. Tries to exit
+# 3. Stop hook blocks exit
+# 4. Stop hook feeds the SAME prompt back
+# 5. Repeat until completion
+```
+
+The loop happens **inside your current session** - you don't need external bash loops. The Stop hook in `hooks/stop-hook.sh` creates the self-referential feedback loop by blocking normal session exit.
+
+This creates a **self-referential feedback loop** where:
+- The prompt never changes between iterations
+- Claude's previous work persists in files
+- Each iteration sees modified files and git history
+- Claude autonomously improves by reading its own past work in files
+
+## Quick Start
+
+```bash
+/ralph-loop "Build a REST API for todos. Requirements: CRUD operations, input validation, tests. Output <promise>COMPLETE</promise> when done." --completion-promise "COMPLETE" --max-iterations 50
+```
+
+Claude will:
+- Implement the API iteratively
+- Run tests and see failures
+- Fix bugs based on test output
+- Iterate until all requirements met
+- Output the completion promise when done
+
+## Commands
+
+### /ralph-loop
+
+Start a Ralph loop in your current session.
+
+**Usage:**
+```bash
+/ralph-loop "<prompt>" --max-iterations <n> --completion-promise "<text>"
+```
+
+**Options:**
+- `--max-iterations <n>` - Stop after N iterations (default: unlimited)
+- `--completion-promise <text>` - Phrase that signals completion
+
+### /cancel-ralph
+
+Cancel the active Ralph loop.
+
+**Usage:**
+```bash
+/cancel-ralph
+```
+
+## Prompt Writing Best Practices
+
+### 1. Clear Completion Criteria
+
+❌ Bad: "Build a todo API and make it good."
+
+✅ Good:
+```markdown
+Build a REST API for todos.
+
+When complete:
+- All CRUD endpoints working
+- Input validation in place
+- Tests passing (coverage > 80%)
+- README with API docs
+- Output: <promise>COMPLETE</promise>
+```
+
+### 2. Incremental Goals
+
+❌ Bad: "Create a complete e-commerce platform."
+
+✅ Good:
+```markdown
+Phase 1: User authentication (JWT, tests)
+Phase 2: Product catalog (list/search, tests)
+Phase 3: Shopping cart (add/remove, tests)
+
+Output <promise>COMPLETE</promise> when all phases done.
+```
+
+### 3. Self-Correction
+
+❌ Bad: "Write code for feature X."
+
+✅ Good:
+```markdown
+Implement feature X following TDD:
+1. Write failing tests
+2. Implement feature
+3. Run tests
+4. If any fail, debug and fix
+5. Refactor if needed
+6. Repeat until all green
+7. Output: <promise>COMPLETE</promise>
+```
+
+### 4. Escape Hatches
+
+Always use `--max-iterations` as a safety net to prevent infinite loops on impossible tasks:
+
+```bash
+# Recommended: Always set a reasonable iteration limit
+/ralph-loop "Try to implement feature X" --max-iterations 20
+
+# In your prompt, include what to do if stuck:
+# "After 15 iterations, if not complete:
+#  - Document what's blocking progress
+#  - List what was attempted
+#  - Suggest alternative approaches"
+```
+
+**Note**: The `--completion-promise` uses exact string matching, so you cannot use it for multiple completion conditions (like "SUCCESS" vs "BLOCKED"). Always rely on `--max-iterations` as your primary safety mechanism.
+
+## Philosophy
+
+Ralph embodies several key principles:
+
+### 1. Iteration > Perfection
+Don't aim for perfect on first try. Let the loop refine the work.
+
+### 2. Failures Are Data
+"Deterministically bad" means failures are predictable and informative. Use them to tune prompts.
+
+### 3. Operator Skill Matters
+Success depends on writing good prompts, not just having a good model.
+
+### 4. Persistence Wins
+Keep trying until success. The loop handles retry logic automatically.
+
+## When to Use Ralph
+
+**Good for:**
+- Well-defined tasks with clear success criteria
+- Tasks requiring iteration and refinement (e.g., getting tests to pass)
+- Greenfield projects where you can walk away
+- Tasks with automatic verification (tests, linters)
+
+**Not good for:**
+- Tasks requiring human judgment or design decisions
+- One-shot operations
+- Tasks with unclear success criteria
+- Production debugging (use targeted debugging instead)
+
+## Real-World Results
+
+- Successfully generated 6 repositories overnight in Y Combinator hackathon testing
+- One $50k contract completed for $297 in API costs
+- Created entire programming language ("cursed") over 3 months using this approach
+
+## Learn More
+
+- Original technique: https://ghuntley.com/ralph/
+- Ralph Orchestrator: https://github.com/mikeyobrien/ralph-orchestrator
+
+## For Help
+
+Run `/help` in Claude Code for detailed command reference and examples.