docs: add context packing tools section and Osmani workflow reference

- New section "12. Context Packing Tools" in ai-ecosystem.md
  documenting gitingest, repo2txt usage patterns
- Added Addy Osmani "My AI Coding Workflow in 2026" to methodologies.md
  sources (validates spec-first, TDD, git checkpoints)
- Updated reference.yaml with ai_ecosystem_context_packing entry

Source: https://addyosmani.com/blog/ai-coding-workflow/

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

CHANGELOG.md

@@ -8,6 +8,16 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 ### Added
 
+- **Context Packing Tools section** (`guide/ai-ecosystem.md:1114`)
+  - New section "12. Context Packing Tools" documenting gitingest, repo2txt usage patterns
+  - Clarifies when to use external context extraction vs native Claude Code file access
+  - Updated Table of Contents with sections 11 (AI Coding Agents Matrix) and 12
+  - **machine-readable/reference.yaml**: Added `ai_ecosystem_context_packing` entry
+
+- **Addy Osmani AI Coding Workflow reference** (`guide/methodologies.md:313`)
+  - Added "My AI Coding Workflow in 2026" article to SDD & Spec-First sources
+  - Validates spec-first, TDD, git checkpoints workflow patterns
+
 - **MCP Tool Search documentation** (`guide/architecture.md`)
   - New section "MCP Tool Search (Lazy Loading)" with complete technical details
   - Explains how Claude Code uses Anthropic's Advanced Tool Use API feature (v2.1.7+)

guide/ai-ecosystem.md

@@ -19,6 +19,8 @@
 - [8. Workflow Orchestration](#8-workflow-orchestration)
 - [9. Cost & Subscription Strategy](#9-cost--subscription-strategy)
 - [10. Claude Cowork (Research Preview)](#10-claude-cowork-research-preview)
+- [11. AI Coding Agents Matrix](#11-ai-coding-agents-matrix)
+- [12. Context Packing Tools](#12-context-packing-tools)
 - [Appendix: Ready-to-Use Prompts](#appendix-ready-to-use-prompts)
 - [Alternative Providers (Community Workarounds)](#alternative-providers-community-workarounds)
 
@@ -1111,6 +1113,42 @@ An **interactive comparison matrix** of 23 AI coding agents across 11 technical
 
 ---
 
+## 12. Context Packing Tools
+
+When working with LLMs on large codebases, **context packing** refers to techniques for extracting and feeding relevant code context to the model efficiently.
+
+### Why Context Matters
+
+Claude Code automatically reads files as needed, but external tools exist for:
+- **Pre-session preparation**: Dump relevant code before starting
+- **Cross-tool workflows**: Feed context to models outside Claude Code
+- **Offline analysis**: Prepare context for later use
+
+### Available Tools
+
+| Tool | Purpose | How It Works |
+|------|---------|--------------|
+| **gitingest** | Repo → text dump | Extracts relevant files into a single text file for LLM consumption |
+| **repo2txt** | Repo → formatted context | Similar to gitingest, with formatting options |
+| **Context7 MCP** | Docs lookup | Fetches library documentation on-demand (see [MCP section](./ultimate-guide.md#mcp-servers)) |
+
+### When to Use (and When Not)
+
+| Scenario | Best Approach |
+|----------|---------------|
+| Working in Claude Code | Let Claude read files naturally — no pre-dumping needed |
+| Feeding context to ChatGPT/Gemini | gitingest/repo2txt useful |
+| Preparing spec for team review | Export relevant files to share |
+| Very large monorepo (>1M LOC) | May help with selective extraction |
+
+> **Note**: Claude Code's native file access is usually sufficient. These tools are most useful for cross-tool workflows or when working with models that don't have file system access.
+
+### Source
+
+- Addy Osmani: [My AI Coding Workflow in 2026](https://addyosmani.com/blog/ai-coding-workflow/) — Discusses context packing as part of a broader AI development workflow
+
+---
+
 ## Alternative Providers (Community Workarounds)
 
 > ⚠️ **Disclaimer**: This section documents techniques that exist in the community

guide/methodologies.md

@@ -310,6 +310,7 @@ Recommended stacks by situation:
 
 **SDD & Spec-First**
 - Addy Osmani: [How to Write Good Specs for AI Agents](https://addyosmani.com/blog/good-spec/)
+- Addy Osmani: [My AI Coding Workflow in 2026](https://addyosmani.com/blog/ai-coding-workflow/) — End-to-end workflow: spec-first, context packing, TDD, git checkpoints
 - Martin Fowler: [SDD Tools Analysis](https://martinfowler.com/articles/exploring-gen-ai/sdd-3-tools.html)
 - InfoQ: [Spec-Driven Development](https://www.infoq.com/articles/spec-driven-development/)
 - Kinde: [Beyond TDD - Why SDD is the Next Step](https://kinde.com/learn/ai-for-software-engineering/best-practice/beyond-tdd-why-spec-driven-development-is-the-next-step/)

machine-readable/reference.yaml

@@ -169,6 +169,7 @@ deep_dive:
   ai_ecosystem_workflows: 10590
   ai_ecosystem_integration: 10716
   ai_ecosystem_detailed: "guide/ai-ecosystem.md"
+  ai_ecosystem_context_packing: "guide/ai-ecosystem.md:1114"
   ai_ecosystem_voice_to_text: "guide/ai-ecosystem.md:449"
   ai_ecosystem_alternative_providers: "guide/ai-ecosystem.md:959"
   voice_refine_skill: "examples/skills/voice-refine/SKILL.md"