Fix Gemini protocol status codes and error handling

- Path security violations now return 51 (Not Found) instead of 59 (Bad Request)
- Timeouts return 41 (Server Unavailable) per Gemini spec
- Add comprehensive request validation: empty requests, oversized requests (>1024 bytes), malformed URLs
- Fix CLI argument conflict (config -c vs cert -c)
- Update documentation with status codes, error handling guidelines, and lint checking
- Add environment setup instructions for clippy and cargo PATH

README.md

@@ -22,9 +22,9 @@ Create a config file at `/etc/pollux/config.toml` or use `--config` to specify a
 
 ```toml
 root = "/path/to/static/files"
-cert = "certs/cert.pem"
-key = "certs/key.pem"
-host = "gemini.jeena.net"
+cert = "/path/to/cert.pem"
+key = "/path/to/key.pem"
+host = "gemini.example.com"
 port = 1965
 log_level = "info"
 ```
@@ -33,10 +33,10 @@ log_level = "info"
 
 ### Quick Start with Self-Signed Certs
 ```bash
-mkdir -p dev
+mkdir -p tmp
 openssl req -x509 -newkey rsa:2048 \
-  -keyout dev/key.pem \
-  -out dev/cert.pem \
+  -keyout tmp/key.pem \
+  -out tmp/cert.pem \
   -days 365 \
   -nodes \
   -subj "/CN=localhost"
@@ -44,8 +44,8 @@ openssl req -x509 -newkey rsa:2048 \
 
 Update `config.toml`:
 ```toml
-cert = "dev/cert.pem"
-key = "dev/key.pem"
+cert = "tmp/cert.pem"
+key = "tmp/key.pem"
 ```
 
 Run the server:
@@ -77,15 +77,12 @@ Access with a Gemini client like Lagrange at `gemini://yourdomain.com/`.
 - `--host`: Hostname for validation (required)
 - `--port`: Port to listen on (default 1965)
 
-## Security
-
-Uses path validation to prevent directory traversal. Validate hostnames for production use.
-
 ### Certificate Management
+
 - Never commit certificate files to version control
 - Use development certificates only for local testing
 - Production certificates should be obtained via Let's Encrypt or your CA
 
 ## Testing
 
-Run `cargo test` for unit tests. Fix warnings before commits.
+Run `cargo test` for unit tests. Fix warnings before commits.