v1.4.0: Auto-compact streaming, Bedrock summarization support, subagent orchestration, and Galaxy rebrand continuation

Major features:
- Auto-compact: triggers conversation summarization when context window >= 85%,
  compacts Bedrock message history to a summary pair, and tracks live context tokens
- Bedrock summarization: plumbs `is_summarization` flag through translator/client/response
  pipeline, handles SummarizeConversation input type, and marks `summarized` in metadata
- Session restore: rebuilds bedrock_message_history from persisted task messages via
  newly-public `convert_proto_message`, preventing empty history on reconnect
- Subagent orchestration: adds SubagentQuestion/Answer/CompletionSummary event types,
  parent-child question routing with depth limits, retry counting, and drain methods
- Summarization UI: inline SummarizationView in AI blocks with progress/finished states

Refactors:
- Rename WarpTheme → GalaxyTheme across ~100 files (rebrand continuation)
- Rename warp_home_config_dir → galaxy_home_config_dir and related path functions
- Predefined rules: replace "System Defined Rule #N" with descriptive names
  (e.g. "Correctness Over Speed", "Never Guess") and add lookup helpers
- Usage view: replace cumulative input/output token display with live context tokens,
  cache hit rate calculation, and separate cache read/write stats
- Telemetry: remove verbose doc comments, simplify trait definitions
- Facts view: simplify delete permission check (always allow local deletion)
- Remove warp_managed_paths_watcher.rs (dead code)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/src/ai/agent/api.rs

@@ -139,6 +139,8 @@ pub struct RequestParams {
     /// can store them back into the conversation for the next request cycle.
     pub bedrock_messages_sent:
         std::sync::Arc<std::sync::Mutex<Vec<crate::ai::bedrock::convert::ConversationMessage>>>,
+    /// Whether this request is a conversation summarization/compaction.
+    pub is_summarization: bool,
 }
 
 pub type Event = Result<warp_multi_agent_api::ResponseEvent, Arc<AIApiError>>;
@@ -327,6 +329,7 @@ impl RequestParams {
             agent_name: None,
             bedrock_message_history: Vec::new(),
             bedrock_messages_sent: std::sync::Arc::new(std::sync::Mutex::new(Vec::new())),
+            is_summarization: false,
         }
     }
 }