chore: prepare for open source release (LICENSE, README, CONTRIBUTING)

- Add MIT license
- Rewrite README with features, config, architecture, security docs
- Add CONTRIBUTING.md with development guidelines
- Add open source metadata to both package.json (license, repo, keywords)
- Remove PLAN.md and DEVLOG.md from tracking (local dev files)
- npm audit: 5 moderate vulns in esbuild/vite/vitest (dev-only, fix
  requires breaking major version upgrade, deferred)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: pfillion42

.gitignore

@@ -31,3 +31,7 @@ npm-debug.log*
 
 # Cache
 .cache/
+
+# Project-specific (local only)
+PLAN.md
+DEVLOG.md

CONTRIBUTING.md

@@ -0,0 +1,87 @@
+# Contributing to memviz
+
+Thanks for your interest in contributing! Whether it's a bug report, a feature idea, or a pull request, all contributions are welcome.
+
+## Prerequisites
+
+- Node.js 20+
+- A SQLite-vec database from [MCP Memory Service](https://github.com/doobidoo/mcp-memory-service) (for manual testing)
+
+## Getting started
+
+```bash
+git clone https://github.com/pfillion42/memviz.git
+cd memviz
+
+# Backend
+cd server
+npm install
+cp .env.example .env
+# Set MEMORY_DB_PATH in .env
+
+# Frontend
+cd ../client
+npm install
+```
+
+## Development workflow
+
+The project is a monorepo with two independent packages (`server/` and `client/`). Each has its own `package.json`, tests, and lint config.
+
+```bash
+# Start the backend (auto-reload)
+cd server && npm run dev
+
+# Start the frontend (Vite dev server, proxied to backend)
+cd client && npm run dev
+```
+
+### Running tests
+
+```bash
+cd server && npm test       # Backend tests (Vitest)
+cd client && npm test       # Frontend tests (Vitest + Testing Library)
+```
+
+Both packages also support watch mode:
+
+```bash
+npm run test:watch
+```
+
+### Linting
+
+```bash
+cd server && npm run lint
+cd client && npm run lint
+```
+
+## Code style
+
+- **TypeScript** strict mode in both packages
+- **No accented characters** in code or comments (project convention)
+- **Vitest** for all tests
+- **React Query** hooks for data fetching on the frontend
+- **Zod** schemas for request validation on the backend
+
+## Pull requests
+
+1. Fork the repo and create a branch from `main`
+2. Make your changes
+3. Make sure all tests pass (`npm test` in both `server/` and `client/`)
+4. Make sure lint passes (`npm run lint` in both packages)
+5. Write a clear PR description explaining what changed and why
+
+If you're adding a new feature, please include tests. The project currently has 339 tests and we'd like to keep coverage high.
+
+## Reporting bugs
+
+Open an issue with:
+- What you expected to happen
+- What actually happened
+- Steps to reproduce
+- Your environment (Node version, OS)
+
+## Feature ideas
+
+Open an issue to discuss before starting work on large features. This helps avoid duplicate effort and lets us align on the approach.

DEVLOG.md

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 pfillion42
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.