Add Claude Code deterministic D4D generation framework

This commit adds comprehensive deterministic D4D (Datasheets for Datasets)
generation using Claude Sonnet 4.5 with temperature=0.0 for reproducibility.

## New Files

### D4D YAML Files (Claude Code)
- Concatenated D4D YAMLs: 4 projects (AI_READI, CHORUS, CM4AI, VOICE)
  - Each with comprehensive metadata tracking (SHA-256 hashes, provenance)
- Individual D4D YAMLs: 12 files across all projects
  - GPT-5 generated, Claude Code validated
  - Complete metadata files with reproducibility information

### Documentation
- DETERMINISM.md: Comprehensive guide on deterministic D4D generation
  - Explains model settings (temperature=0.0, pinned version)
  - Documents schema versioning and prompt tracking
  - Describes Claude Code direct synthesis approach
  - Provides verification and comparison procedures

- src/docs/d4d_examples.md: Added Claude Code section
  - Links to synthesized HTML and YAML files
  - Metadata file downloads
  - Explains deterministic features

- CLAUDE.md: Updated with Claude Code D4D generation instructions

### Python Scripts
- src/download/process_concatenated_d4d_claude.py
  - API-based deterministic D4D extraction (temperature=0.0)
  - External prompt loading with SHA-256 tracking
  - Local schema file usage
  - Comprehensive metadata generation

- src/download/process_individual_d4d_claude_direct.py
  - Metadata generator for individually validated D4D files
  - Documents Claude Code validation process

### Prompts (version-controlled)
- src/download/prompts/d4d_concatenated_system_prompt.txt
- src/download/prompts/d4d_concatenated_user_prompt.txt
- src/download/prompts/determinism_settings.yaml

### Makefile Updates
- Added extract-d4d-concat-claude targets
- Added extract-d4d-individual-claude targets
- Added list-d4d-individual-claude target
- Comprehensive documentation in comments

## Key Features

1. **Deterministic Settings**
   - Temperature: 0.0 (maximum determinism)
   - Model: claude-sonnet-4-5-20250929 (date-pinned)
   - Schema: Local file (version-controlled)
   - Prompts: External files (version-controlled)

2. **Comprehensive Metadata**
   - SHA-256 hashes: input files, schema, prompts
   - Processing environment details
   - Git commit provenance
   - Reproducibility commands

3. **Two Implementation Paths**
   - API-based: process_concatenated_d4d_claude.py (requires ANTHROPIC_API_KEY)
   - Direct synthesis: Claude Code assistant (current files)

4. **Make Targets**
   - make extract-d4d-concat-claude PROJECT=AI_READI
   - make extract-d4d-concat-all-claude
   - make extract-d4d-individual-claude
   - make list-d4d-individual-claude

## Statistics

- Concatenated: 4 D4D YAMLs + 4 metadata files
- Individual: 12 D4D YAMLs + 12 metadata files
- Total: 16 D4D YAMLs with complete provenance tracking

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

Co-Authored-By: Claude <[email protected]>

Author: realmarcin

CLAUDE.md

@@ -343,6 +343,9 @@ make data-status
 
 # Quick compact overview
 make data-status-quick
+
+# Detailed D4D YAML size report
+make data-d4d-sizes
 ```
 
 **Features:**
@@ -351,6 +354,7 @@ make data-status-quick
 - Identifies missing directories with ❌ markers
 - Displays file sizes and line counts for key files
 - Provides summary statistics across all projects
+- Reports D4D YAML sizes with individual and concatenated breakdowns
 
 ### Quick Reference: Common Workflows
 
@@ -507,6 +511,7 @@ Beyond standard LinkML targets, this project adds comprehensive D4D pipeline tar
 ```bash
 make data-status                         # Full data status report with counts
 make data-status-quick                   # Compact status overview
+make data-d4d-sizes                      # Detailed D4D YAML size report
 ```
 
 ### Concatenation Targets