docs: add contributing guide and CI badge

CONTRIBUTING.md

@@ -0,0 +1,98 @@
+# Contributing
+
+Thanks for helping improve agent-browser. This guide covers the local setup,
+coding standards, and pull request process for contributors.
+
+## Development Setup
+
+### Prerequisites
+
+- Node.js 22 or newer
+- pnpm
+- Rust stable toolchain
+- Chrome or Chrome for Testing for end-to-end tests
+
+Install dependencies:
+
+```bash
+pnpm install
+```
+
+Build the TypeScript package and native CLI:
+
+```bash
+pnpm build:native
+```
+
+Install Chrome for browser automation tests:
+
+```bash
+cargo run --manifest-path cli/Cargo.toml -- install
+```
+
+On Linux, include system dependencies:
+
+```bash
+cargo run --manifest-path cli/Cargo.toml -- install --with-deps
+```
+
+## Common Commands
+
+Run the Rust test suite:
+
+```bash
+cargo test --manifest-path cli/Cargo.toml
+```
+
+Check Rust formatting:
+
+```bash
+cargo fmt --manifest-path cli/Cargo.toml -- --check
+```
+
+Run Clippy:
+
+```bash
+cargo clippy --manifest-path cli/Cargo.toml -- -D warnings
+```
+
+Run ignored end-to-end tests serially:
+
+```bash
+cargo test --profile ci --manifest-path cli/Cargo.toml e2e -- --ignored --test-threads=1
+```
+
+Check package version synchronization:
+
+```bash
+node scripts/check-version-sync.js
+```
+
+## Coding Style
+
+- Use pnpm for package management.
+- Keep CLI flags in kebab-case, such as `--auto-connect`.
+- Do not hardcode ANSI escape sequences. Use `cli/src/color.rs` for colored CLI output.
+- Keep user-facing documentation in sync with behavior changes.
+- Use concise, direct documentation and examples.
+- Avoid unrelated refactors in small fixes.
+
+When adding or changing user-facing CLI behavior, update every relevant surface:
+
+- `cli/src/output.rs`
+- `README.md`
+- `skills/agent-browser/SKILL.md`
+- `docs/src/app/`
+- Inline doc comments in the related source files
+
+## Pull Request Process
+
+1. Create a focused branch from `main`.
+2. Make the smallest change that fully solves the issue.
+3. Run the relevant checks locally before opening a pull request.
+4. Include a clear summary, changed files, and verification notes in the PR body.
+5. Link the related issue with `Closes #<issue-number>` when applicable.
+
+For bounty submissions, include the bounty reference requested by the issue in
+the pull request body.
+

README.md

@@ -1,5 +1,7 @@
 # agent-browser
 
+[![CI](https://github.com/dextonai/agent-browser/actions/workflows/ci.yml/badge.svg)](https://github.com/dextonai/agent-browser/actions/workflows/ci.yml)
+
 Browser automation CLI for AI agents. Fast native Rust CLI.
 
 ## Installation