fix: flatten tool messages for NEAR AI cloud-api compatibility (#41)

* fix: flatten tool messages for NEAR AI cloud-api compatibility

NEAR AI cloud-api does not support the OpenAI multi-turn tool-calling
protocol (role:"tool" messages cause HTTP 400). This adds a
flatten_tool_messages() pass in NearAiChatProvider that rewrites
assistant tool_call messages and tool result messages into plain
assistant/user text before sending to the API. The model still sees
the tool execution history, just in a text format it can process.

Also includes a minor fix to telegram channel send_pairing_reply
for updated WASM host function signature.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* fix: resolve CI failures in fmt, rate limiting, and test configuration

- Apply cargo fmt to nearai_chat.rs formatting violations
- Fix truncate(true) bug in record_failed_approve that cleared the
  attempts file before reading, preventing rate limit from ever
  triggering
- Skip bundled channel test when WASM build artifacts are unavailable
  (CI lacks wasm32-wasip2 target)
- Split CI test workflow to exclude workspace_integration tests that
  require PostgreSQL

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* fix: resolve clippy unnecessary_unwrap lint (Rust 1.93)

Replace is_some() + unwrap() pattern with if-let binding to satisfy
clippy::unnecessary_unwrap which is now deny-by-default.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

---------

Co-authored-by: Claude Opus 4.6 <[email protected]>
Co-authored-by: firat.sertgoz <[email protected]>
Co-authored-by: Illia Polosukhin <[email protected]>

channels-src/telegram/src/lib.rs

@@ -856,6 +856,7 @@ fn send_pairing_reply(chat_id: i64, code: &str) -> Result<(), String> {
         "https://api.telegram.org/bot{TELEGRAM_BOT_TOKEN}/sendMessage",
         &headers.to_string(),
         Some(&payload_bytes),
+        None,
     );
 
     match result {