ci: add automated crate publishing workflow

- Add publish workflow that triggers on version tags (v*)
- Include Rust caching for faster CI builds
- Verify tag version matches Cargo.toml before publishing
- Update README with crates.io and CI status badges
- Move installation instructions to top of README

🤖 Generated with [Claude Code](https://claude.ai/code)

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

Author: ammario

.github/workflows/publish.yml

@@ -22,6 +22,9 @@ jobs:
         with:
           toolchain: stable
 
+      - name: Setup Rust cache
+        uses: Swatinem/rust-cache@v2
+      
       - name: Verify version matches tag
         run: |
           # Extract version from Cargo.toml

README.md

@@ -1,7 +1,32 @@
 # httpjail
 
+[![Crates.io](https://img.shields.io/crates/v/httpjail.svg)](https://crates.io/crates/httpjail)
+[![CI](https://github.com/coder/httpjail/actions/workflows/tests.yml/badge.svg)](https://github.com/coder/httpjail/actions/workflows/tests.yml)
+
 A cross-platform tool for monitoring and restricting HTTP/HTTPS requests from processes using network isolation and transparent proxy interception.
 
+## Installation
+
+### Install via Cargo
+
+```bash
+cargo install httpjail
+```
+
+### Install from source
+
+```bash
+# Clone the repository
+git clone https://github.com/coder/httpjail
+cd httpjail
+
+# Build with Cargo
+cargo build --release
+
+# Install to PATH
+sudo cp target/release/httpjail /usr/local/bin/
+```
+
 ## Features
 
 - 🔒 **Process-level network isolation** - Isolate processes in restricted network environments
@@ -96,44 +121,20 @@ httpjail creates an isolated network environment for the target process, interce
 | Sudo required     | ⚠️ Yes                   | ✅ No                       | 🚧            |
 | Force all traffic | ✅ Yes                   | ❌ No (apps must cooperate) | 🚧            |
 
-## Installation
-
-### Prerequisites
+## Prerequisites
 
-#### Linux
+### Linux
 
 - Linux kernel 3.8+ (network namespace support)
 - nftables (nft command)
 - libssl-dev (for TLS)
 - sudo access (for namespace creation)
 
-#### macOS
+### macOS
 
 - macOS 10.15+ (Catalina or later)
 - No special permissions required (runs in weak mode)
 
-### Install from source
-
-```bash
-# Clone the repository
-git clone https://github.com/yourusername/httpjail
-cd httpjail
-
-# Build with Cargo
-cargo build --release
-
-# Install to PATH
-sudo cp target/release/httpjail /usr/local/bin/
-
-# CA certificate is auto-generated on first run
-```
-
-### Install via Cargo
-
-```bash
-cargo install httpjail
-```
-
 ## Usage Examples
 
 ### Basic Usage