Report diagnostic upload failures (#39287)

## Why

Submitting a diagnostic report could appear successful without confirming that Sentry accepted the upload, leaving callers unable to detect transport or HTTP failures.

## What changed

- Send report envelopes through the route-aware HTTP client and await the response.
- Reject redirects, propagate transport and non-success HTTP responses, and include the full error chain in upload JSON-RPC errors.
- Add structured logs for upload attempts, successes, and failures without including report contents.

## Testing

Added coverage for successful uploads, rejected responses, blocked redirects, transport failures, and app-server JSON-RPC error reporting.

GitOrigin-RevId: 07b5cfccd7a65f35d51a720537d2cd8962ed6cdb

codex-rs/feedback/Cargo.toml

@@ -9,6 +9,7 @@ workspace = true
 
 [dependencies]
 anyhow = { workspace = true }
+codex-http-client = { workspace = true }
 codex-login = { workspace = true }
 codex-protocol = { workspace = true }
 mime_guess = { workspace = true }
@@ -19,6 +20,8 @@ tracing-subscriber = { workspace = true }
 [dev-dependencies]
 log = { workspace = true }
 pretty_assertions = { workspace = true }
+tokio = { workspace = true, features = ["macros", "rt"] }
+wiremock = { workspace = true }
 
 [lib]
 doctest = false