initial commit: ralph-loop extension

- DAG-based task execution with dependency resolution
- Persistent progress tracking in .ralph/progress.json
- Reflection system for cross-task context
- Support for Fio README, checkbox, and YAML formats
- Retry with exponential backoff
- Parallel batch execution

skills/ralph-task/SKILL.md

@@ -0,0 +1,34 @@
+# ralph-task
+
+Execute a single task from a ralph task file.
+
+## When to Use
+
+- User asks to execute a specific task from a task file
+- User provides a task ID and wants to run it
+- User wants to run the next task in sequence
+
+## Usage
+
+```
+/ralph run [task-file]      # Run all tasks
+/ralph next [task-file]     # Run next batch
+/ralph status [task-file]   # Check progress
+```
+
+## Task File Location
+
+Default: `README.md` in current directory. Can be overridden with explicit path.
+
+## Reflection Format
+
+After completing a task, include:
+
+```
+## REFLECTION
+SUMMARY: [what was done]
+FILES: [files changed]
+LEARNINGS:
+- [key learning]
+BLOCKERS: [issues or 'none']
+```