DNS resolver customization (DoH/DoT/plain), hickory-resolver 0.26 upgrade, and minor fixes

crates/primp-python/Cargo.toml

@@ -20,6 +20,7 @@ pyo3-log = "0.13.2"
 primp = { version = "1.2", path = "../primp", features = [
     "impersonate",
     "socks",
+    "hickory-dns",
 ] }
 bytes = "1"
 encoding_rs = { version = "0.8.35" }

crates/primp-python/docs/async_client.md

@@ -26,6 +26,7 @@ primp.AsyncClient(
     ca_cert_file=None,
     https_only=False,
     http2_only=False,
+    dns_resolver=None,
     base_url=None,
     cookies=None,
 )

crates/primp-python/docs/client.md

@@ -24,6 +24,7 @@ primp.Client(
     ca_cert_file=None,      # Path to CA certificate
     https_only=False,       # HTTPS only mode
     http2_only=False,       # HTTP/2 only mode
+    dns_resolver=None,      # DNS resolver: str, list[str], or None (see docs/dns.md)
     base_url=None,          # Base URL for relative paths
     cookies=None,           # Initial cookies to send with all requests
 )

crates/primp-python/docs/dns.md

@@ -0,0 +1,73 @@
+# DNS Resolution
+
+Control how DNS lookups are performed by passing `dns_resolver` to `Client()` or `AsyncClient()`.
+
+## Quick Reference
+
+| Value | Behavior |
+|-------|----------|
+| `None` (default) | System resolver |
+| `"system"` | System resolver |
+| `"doh://.../dns-query"` | DNS-over-HTTPS |
+| `"dot://1.1.1.1"` | DNS-over-TLS |
+| `"dns://1.1.1.1"` | Plain DNS on port 53 |
+| `"1.1.1.1"` | Plain DNS on port 53 (shorthand) |
+| `["doh://...", "dot://..."]` | Fallback chain (first success wins) |
+
+## Examples
+
+**System resolver (default):**
+```python
+client = primp.Client()
+```
+
+**DNS-over-HTTPS via Cloudflare:**
+```python
+client = primp.Client(dns_resolver="doh://cloudflare-dns.com/dns-query")
+```
+
+**DNS-over-TLS:**
+```python
+client = primp.Client(dns_resolver="dot://1.1.1.1")
+```
+
+**Plain DNS:**
+```python
+client = primp.Client(dns_resolver="1.1.1.1")
+# or explicitly:
+client = primp.Client(dns_resolver="dns://1.1.1.1")
+```
+
+**Fallback chain: try DoH first, fall back to plain DNS:**
+```python
+client = primp.Client(dns_resolver=["doh://cloudflare-dns.com/dns-query", "1.1.1.1"])
+```
+
+**Fallback chain including system resolver:**
+```python
+client = primp.Client(dns_resolver=["doh://cloudflare-dns.com/dns-query", "system", "1.1.1.1"])
+```
+
+**Async:**
+```python
+client = primp.AsyncClient(dns_resolver="dot://dns.google")
+```
+
+## Order Matters
+
+Resolvers in a list are tried in order. The first one that succeeds wins.
+
+```python
+# Try DoH first, fall back to system
+client = primp.Client(dns_resolver=["doh://cloudflare-dns.com/dns-query", "system"])
+```
+
+## Scheme Reference
+
+| Scheme | Protocol | Default Port | Example |
+|--------|----------|-------------|---------|
+| `doh://` | HTTPS (DoH) | 443 | `doh://cloudflare-dns.com/dns-query` |
+| `dot://` | TLS (DoT) | 853 | `dot://1.1.1.1` |
+| `dns://` | UDP/TCP | 53 | `dns://8.8.8.8` |
+| *(none)* | UDP/TCP (plain) | 53 | `1.1.1.1` |
+| `system` | OS `getaddrinfo` | — | `system` |