Merge main into feature/add-qwen-support

Combines Qwen Code support with new script variant structure from main.
Key additions:
- Qwen Code AI assistant support
- PowerShell script variants alongside Bash
- Updated release packaging for per-script variants
- Maintains all existing Cursor support from main

Co-authored-by: Claude <noreply@anthropic.com>

templates/plan-template.md

@@ -1,5 +1,8 @@
 # Implementation Plan: [FEATURE]
 
+<!-- VARIANT:sh - Run `/scripts/bash/update-agent-context.sh __AGENT__` for your AI assistant -->
+<!-- VARIANT:ps - Run `/scripts/powershell/update-agent-context.ps1 -AgentType __AGENT__` for your AI assistant -->
+
 **Branch**: `[###-feature-name]` | **Date**: [DATE] | **Spec**: [link]
 **Input**: Feature specification from `/specs/[###-feature-name]/spec.md`
 
@@ -171,7 +174,7 @@ ios/ or android/
    - Quickstart test = story validation steps
 
 5. **Update agent file incrementally** (O(1) operation):
-   - Run `/scripts/update-agent-context.sh [claude|gemini|copilot|qwen]` for your AI assistant
+   VARIANT-INJECT
    - If exists: Add only NEW tech from current plan
    - Preserve manual additions between markers
    - Update recent changes (keep last 3)