Add human-focused README.md to every skill and bundle directory

Each README is written for a human audience, explaining:
- What the skill does (not what format it follows)
- What benefit the user gets from installing it
- Quick setup and usage patterns
- When to load/trigger the skill
- What scripts, references, and templates it ships

data-scientist already had a README — left unchanged.

48 READMEs added across all skill and bundle directories.

systematic-debugging/README.md

@@ -0,0 +1,28 @@
+# Systematic Debugging — 4-Phase Root Cause Protocol
+
+A disciplined 4-phase protocol for debugging technical issues: understand bugs before fixing. No random fixes, no symptom patching — only root cause investigation.
+
+## Why Install This Skill
+
+When your agent loads this skill, it becomes a **disciplined debugger** who follows a proven protocol. That means:
+
+- **Phase 1: Understand the bug** — reproduce, characterize, and scope before touching any code
+- **Phase 2: Find root cause** — trace symptom to source with evidence, not guesses
+- **Phase 3: Fix root cause** — one fix per root cause, validated before committing
+- **Phase 4: Verify and learn** — test the fix, check for similar issues, document the lesson
+- **Specialized patterns** — schema/environment divergence, exception chain analysis, dependency source detection, API failure characterization
+
+## What You Get
+
+| Directory | Purpose |
+|-----------|---------|
+| `SKILL.md` | The Iron Law, phase-by-phase protocol, specialized debugging patterns |
+| `references/` | Deep dives into each phase, specialized pattern guides, diagnostics |
+
+## Triggers
+
+Load this for ANY technical issue — test failures, production bugs, unexpected behavior, performance problems, build failures, integration issues. ESPECIALLY when under time pressure.
+
+## Requirements
+
+Platform-agnostic. Some sections cover macOS-specific sandbox debugging patterns. Requires access to source code and testing tools.