v1.5.0: Inline subagent panels, Bedrock compaction fixes, context window debug view

New features:
- Inline subagent panels with expand/collapse and click-to-toggle
- /context slash command to inspect bedrock_message_history
- Child-to-parent question routing with auto-answer for subagents
- Subagent token usage and cost merging into parent conversation
- Randomized session-colored user avatar silhouettes

Bug fixes:
- Bedrock: remove orphaned tool_results after compaction
- Bedrock: self-healing exchange lookup for out-of-order streaming
- Bedrock: append continuation prompt when conversation ends with assistant
- Duration sanity check rejects epoch-time artifacts from session restore
- Cache hit rate calculation uses actual total_input_tokens
- Hide "Time to first token" when value is zero

Improvements:
- Demote verbose bedrock-debug logs to debug/trace levels
- Bedrock tool usage counting falls back to action counting
- Remove logout menu item from workspace menu

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

app/Cargo.toml

@@ -5,7 +5,7 @@ description = "Galaxy - AI-powered terminal"
 edition = "2021"
 autobins = false
 name = "galaxy"
-version = "1.3.0"
+version = "1.5.0"
 publish.workspace = true
 license.workspace = true