feat: add post3 s3 proxy for postgresql

Signed-off-by: kjuulh <contact@kjuulh.io>

crates/post3-sdk/examples/aws_sdk_direct.rs

@@ -0,0 +1,107 @@
+//! Use aws-sdk-s3 directly against post3 (without the post3-sdk wrapper).
+//! Shows the raw configuration needed.
+//!
+//! Prerequisites: post3-server running on localhost:9000
+//!   mise run up && mise run dev
+//!
+//! Run:
+//!   cargo run -p post3-sdk --example aws_sdk_direct
+
+use post3_sdk::aws_sdk_s3;
+
+#[tokio::main]
+async fn main() -> anyhow::Result<()> {
+    let endpoint = std::env::var("POST3_ENDPOINT")
+        .unwrap_or_else(|_| "http://localhost:9000".to_string());
+
+    // Configure aws-sdk-s3 manually for post3
+    let creds = aws_sdk_s3::config::Credentials::new(
+        "test",      // access key (any value works when auth is disabled)
+        "test",      // secret key
+        None,        // session token
+        None,        // expiry
+        "example",   // provider name
+    );
+
+    let config = aws_sdk_s3::Config::builder()
+        .behavior_version_latest()
+        .region(aws_sdk_s3::config::Region::new("us-east-1"))
+        .endpoint_url(&endpoint)
+        .credentials_provider(creds)
+        .force_path_style(true) // Required: post3 uses path-style, not virtual-hosted
+        .build();
+
+    let client = aws_sdk_s3::Client::from_conf(config);
+
+    // Create bucket
+    println!("Creating bucket...");
+    client
+        .create_bucket()
+        .bucket("direct-bucket")
+        .send()
+        .await?;
+
+    // Put object
+    println!("Putting object...");
+    client
+        .put_object()
+        .bucket("direct-bucket")
+        .key("greeting.txt")
+        .body(Vec::from(&b"Hello from aws-sdk-s3!"[..]).into())
+        .send()
+        .await?;
+
+    // Get object
+    let resp = client
+        .get_object()
+        .bucket("direct-bucket")
+        .key("greeting.txt")
+        .send()
+        .await?;
+    let body = resp.body.collect().await?.into_bytes();
+    println!("Got: {}", String::from_utf8_lossy(&body));
+
+    // List objects
+    let list = client
+        .list_objects_v2()
+        .bucket("direct-bucket")
+        .send()
+        .await?;
+    println!("Objects:");
+    for obj in list.contents() {
+        println!(
+            "  {} ({} bytes)",
+            obj.key().unwrap_or("?"),
+            obj.size().unwrap_or(0)
+        );
+    }
+
+    // Head object
+    let head = client
+        .head_object()
+        .bucket("direct-bucket")
+        .key("greeting.txt")
+        .send()
+        .await?;
+    println!(
+        "Head: size={}, etag={:?}",
+        head.content_length().unwrap_or(0),
+        head.e_tag()
+    );
+
+    // Cleanup
+    client
+        .delete_object()
+        .bucket("direct-bucket")
+        .key("greeting.txt")
+        .send()
+        .await?;
+    client
+        .delete_bucket()
+        .bucket("direct-bucket")
+        .send()
+        .await?;
+    println!("Done!");
+
+    Ok(())
+}