replace ContainerRuntime CLI to Bollard crate (default: docker socket)

limit tool result to open router tool response (with truncated info for
ai)

Hard kill if graceful shutdown is too long

crates/herald-server/src/consts.rs

@@ -15,7 +15,8 @@ pub const SANDBOX_SYSTEM_PROMPT: &str = "
     tools (ls, read_file, grep, find) to explore the code and gather the context
     you need before answering. Paths are relative to the repository root.
 
-    When you have enough information, answer with the requested JSON only.
+    When you have enough information, answer with the requested JSON only, as a raw
+    JSON object: no markdown code fence, nothing before or after it.
 ";
 
 pub const REVIEW_PROMPT: &str = "
@@ -39,6 +40,8 @@ pub const REVIEW_PROMPT: &str = "
 
     Return your feedback, in french, with only this json format, reviews must contain each review
     All fields are mandatory.
+    Answer with the raw json object only: no markdown code fence, no text before or
+    after it.
     (filename field must contain the full path with extension; line must be one of the
     listed line numbers for that file, and side must be \"added\" when the line comes
     from the `added` list or \"removed\" when it comes from the `removed` list)