docs: sync documentation from private repo

- Rewrite 3_context-and-memory.md (auto-context system, remove legacy memory)
- Create 7_voice.md (voice interface documentation)
- Update 0_overview.md, 1_architecture.md, 4_tools-and-workflows.md, 6_ui.md, 8_mcp.md
- Add simple human-readable intros to all docs
- Update README.md with voice doc reference

Synced from ra-h commit 4a3d7e0

docs/README.md

@@ -1,21 +1,46 @@
-# Documentation
+# RA-H Documentation
 
-## Quick Start
-See the main [README.md](../README.md) for setup instructions.
+Technical documentation for RA-H — AI-powered knowledge management.
 
-## Architecture
+## Quick Links
 
-| Document | Description |
-|----------|-------------|
-| [0_overview.md](0_overview.md) | System overview and philosophy |
-| [1_architecture.md](1_architecture.md) | Technical architecture |
-| [2_schema.md](2_schema.md) | Database schema and sqlite-vec setup |
-| [3_context-and-memory.md](3_context-and-memory.md) | Context system |
-| [4_tools-and-workflows.md](4_tools-and-workflows.md) | Agent tools and workflows |
-| [5_logging-and-evals.md](5_logging-and-evals.md) | Logging infrastructure |
-| [6_ui.md](6_ui.md) | UI components and patterns |
-| [8_mcp.md](8_mcp.md) | MCP server setup |
-| [9_open-source.md](9_open-source.md) | Open source specific notes |
+- **Website:** [ra-h.app](https://ra-h.app)
+- **Download:** [ra-h.app/download](https://ra-h.app/download)
+- **Open Source:** [github.com/bradwmorris/ra-h_os](https://github.com/bradwmorris/ra-h_os)
 
-## Troubleshooting
-See [TROUBLESHOOTING.md](TROUBLESHOOTING.md) for common issues.
+## Documentation Index
+
+| # | Document | Description |
+|---|----------|-------------|
+| 0 | [Overview](./0_overview.md) | What is RA-H, design philosophy, tech stack |
+| 1 | [Architecture](./1_architecture.md) | Agent hierarchy, system design |
+| 2 | [Schema](./2_schema.md) | Database schema, nodes, edges, embeddings |
+| 3 | [Context & Memory](./3_context-and-memory.md) | Auto-context system, how agents see your knowledge |
+| 4 | [Tools & Workflows](./4_tools-and-workflows.md) | Available tools, editable workflows |
+| 5 | [Logging & Evals](./5_logging-and-evals.md) | Debugging, evaluation framework |
+| 6 | [UI](./6_ui.md) | 3-panel layout, views, Settings |
+| 7 | [Voice](./7_voice.md) | Voice interface (STT/TTS) |
+| 8 | [MCP Server](./8_mcp.md) | External agent connector (Claude Code, etc.) |
+| 9 | [Open Source](./9_open-source.md) | Sync strategy, repo differences |
+
+## For Users
+
+Start here:
+1. [Overview](./0_overview.md) — What RA-H is and how it works
+2. [MCP Server](./8_mcp.md) — Connect Claude Code to your knowledge base
+
+## For Developers
+
+If you're contributing or self-hosting:
+1. [Architecture](./1_architecture.md) — Understand the agent hierarchy
+2. [Schema](./2_schema.md) — Database structure
+3. [Tools & Workflows](./4_tools-and-workflows.md) — How to extend RA-H
+4. [Open Source](./9_open-source.md) — Contribution workflow
+
+## Development Process
+
+Internal development docs are in `docs/development/`:
+- `process/` — Workflow, handoff, kickstart
+- `backlog/` — Task backlog
+- `prd-*.md` — Product requirement documents
+- `completed/` — Archived PRDs