feat: add ecosystem positioning, install script & new commands

Ecosystem & Positioning:
- Add README section with competitive positioning (davila7, awesome-claude-code, wesammustafa)
- Add comparison table highlighting unique features (architecture, TDD/SDD, quiz, YAML index)
- Add ecosystem section to reference.yaml

Template Installation:
- Add scripts/install-templates.sh for one-liner template installation
- Support for agents, hooks, commands, skills, memory templates

New Commands:
- catchup, explain, optimize, refactor, security, ship

New Content:
- Semantic anchors catalog and documentation
- Extended guide content (+470 lines)

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

examples/commands/explain.md

@@ -0,0 +1,166 @@
+# Code Explainer
+
+Explain code, concepts, or system behavior with adjustable depth levels.
+
+## Purpose
+
+Get clear explanations of:
+- How specific code works
+- Why certain patterns are used
+- What a system/module does
+- Architectural decisions and trade-offs
+
+## Instructions
+
+### Step 1: Determine Scope
+
+Identify what needs explanation:
+- **File**: Entire file structure and purpose
+- **Function/Method**: Specific implementation details
+- **Concept**: Architectural pattern or design decision
+- **Flow**: How data/control moves through the system
+
+### Step 2: Assess Complexity
+
+```
+Simple (1-2 min read)     → Quick summary, key points only
+Standard (3-5 min read)   → Purpose, how it works, key decisions
+Deep (10+ min read)       → Full breakdown, alternatives, trade-offs
+```
+
+### Step 3: Gather Context
+
+```bash
+# For file explanations
+head -50 "$FILE"  # See imports and structure
+
+# For function explanations
+grep -A 30 "function $NAME\|def $NAME\|fn $NAME" "$FILE"
+
+# For module explanations
+ls -la "$DIR"
+cat "$DIR/index.ts" 2>/dev/null || cat "$DIR/__init__.py" 2>/dev/null
+```
+
+### Step 4: Structure the Explanation
+
+## Output Format
+
+---
+
+### 📖 Explanation: [Target]
+
+**Scope**: [file/function/concept/flow]
+**Depth**: [simple/standard/deep]
+
+### What It Does
+
+[1-3 sentences describing the purpose]
+
+### How It Works
+
+[Step-by-step breakdown appropriate to depth level]
+
+### Key Decisions
+
+| Decision | Why | Alternative |
+|----------|-----|-------------|
+| [choice made] | [reasoning] | [what else could work] |
+
+### Example Usage
+
+```typescript
+// How to use this correctly
+```
+
+### Related Code
+
+- `path/to/related.ts` - [relationship]
+- `path/to/dependency.ts` - [relationship]
+
+### 💡 Learning Notes (if --learn flag)
+
+[Additional context for understanding the broader pattern]
+
+---
+
+## Depth Levels
+
+### Simple (`/explain --simple`)
+
+```markdown
+**validateUser()** checks if the user object has required fields
+(email, password) and returns a boolean. Uses regex for email format.
+```
+
+### Standard (`/explain` - default)
+
+```markdown
+**validateUser(user: User): ValidationResult**
+
+**Purpose**: Validates user input before database operations.
+
+**Flow**:
+1. Check required fields exist (email, password)
+2. Validate email format with regex
+3. Check password meets requirements (8+ chars, special char)
+4. Return { valid: boolean, errors: string[] }
+
+**Used by**: signup(), updateProfile()
+```
+
+### Deep (`/explain --deep`)
+
+```markdown
+[All of standard, plus:]
+
+**Design Decisions**:
+- Returns ValidationResult instead of throwing to allow batch validation
+- Regex chosen over library for zero dependencies
+- Password rules configurable via config.ts
+
+**Trade-offs**:
+- Pro: Fast, no dependencies
+- Con: Regex email validation isn't RFC-compliant
+
+**Alternatives Considered**:
+- Zod schema: More powerful but adds 50KB
+- Class-validator: Better for decorators but OOP-heavy
+```
+
+## Usage Examples
+
+**Explain a file:**
+```
+/explain src/auth/middleware.ts
+```
+
+**Explain a function:**
+```
+/explain the handleWebhook function in payments.ts
+```
+
+**Explain a concept:**
+```
+/explain how our event sourcing works
+```
+
+**Explain with specific depth:**
+```
+/explain --deep the authentication flow
+/explain --simple what useCallback does
+```
+
+**Explain for learning:**
+```
+/explain --learn the repository pattern used here
+```
+
+## Tips
+
+1. **Be specific**: "Explain line 45-60" > "Explain this file"
+2. **State your level**: "I'm new to TypeScript" helps calibrate
+3. **Ask follow-ups**: "Why not use X instead?" deepens understanding
+4. **Request analogies**: "Explain like I'm familiar with Python but not TS"
+
+$ARGUMENTS