refactor(agents): Complete rewrite of OmO system prompt with Task Complexity assessment

- Added comprehensive Task Complexity assessment before agent delegation (TRIVIAL/EXPLORATION/IMPLEMENTATION/ORCHESTRATION)
- Redefined Explore agent as 'contextual grep' - cheap, parallel background agent for internal codebase search (Level 2 in search strategy)
- Restricted Librarian agent to 3 explicit use cases: Official Documentation, GitHub Context, Famous OSS Implementation
- Added mandatory delegation gate (GATE 2.5) for ALL frontend files (.tsx/.jsx/.vue/.svelte/.css/.scss) - NO direct edits allowed
- Implemented obsessive Todo Management framework with BLOCKING evidence requirements for every action
- Introduced comprehensive Search Strategy Framework with 3-level approach (Direct Tools → Explore → Librarian)
- Restructured Blocking Gates with explicit Pre-Search gate and Pre-Completion verification
- Enhanced Delegation Rules with clear agent purposes and parallelization strategies
- Added Implementation Flow and Exploration Flow with phase-based workflows
- Introduced Decision Matrix for quick action selection
- Enhanced Anti-Patterns section with comprehensive BLOCKING rules for frontend work
- Updated Tool Selection guide with clear preferences (Direct Tools > Agent Tools)
- Improved parallel execution guidelines for explore/librarian agents
- Strengthened verification protocol with evidence requirements

🤖 Generated with assistance of [OhMyOpenCode](https://github.com/code-yeongyu/oh-my-opencode)

src/tools/background-task/constants.ts

@@ -23,17 +23,7 @@ Arguments:
 - block: If true, wait for task completion. If false (default), return current status immediately.
 - timeout: Max wait time in ms when blocking (default: 60000, max: 600000)
 
-Returns:
-- When not blocking: Returns current status with task ID, description, agent, status, duration, and progress info
-- When blocking: Waits for completion, then returns full result
-
-IMPORTANT: The system automatically notifies the main session when background tasks complete.
-You typically don't need block=true - just use block=false to check status, and the system will notify you when done.
-
-Use this to:
-- Check task progress (block=false) - returns full status info, NOT empty
-- Wait for and retrieve task result (block=true) - only when you explicitly need to wait
-- Set custom timeout for long tasks`
+The system automatically notifies when background tasks complete. You typically don't need block=true.`
 
 export const BACKGROUND_CANCEL_DESCRIPTION = `Cancel a running background task.