feat: Suppor mid-turn auto compressions so sufficiently large histories don't create deadlocks for max input tokens

src/config/app_config.rs

@@ -71,6 +71,7 @@ pub struct AppConfig {
     pub compression_threshold: usize,
     pub compression_keep_last: usize,
     pub compression_model: Option<String>,
+    pub compression_safety_valve: f32,
     pub summarization_prompt: Option<String>,
     pub summary_context_prompt: Option<String>,
     pub max_tool_result_chars: Option<usize>,
@@ -164,6 +165,7 @@ impl Default for AppConfig {
             compression_threshold: 4000,
             compression_keep_last: 0,
             compression_model: None,
+            compression_safety_valve: 0.8,
             summarization_prompt: None,
             summary_context_prompt: None,
             max_tool_result_chars: None,
@@ -270,6 +272,7 @@ impl AppConfig {
             compression_threshold: config.compression_threshold,
             compression_keep_last: config.compression_keep_last,
             compression_model: config.compression_model,
+            compression_safety_valve: config.compression_safety_valve,
             summarization_prompt: config.summarization_prompt,
             summary_context_prompt: config.summary_context_prompt,
             max_tool_result_chars: config.max_tool_result_chars,