feat: Add Markdown issue template to support bug report pre-filling

GitHub's YAML templates (.yml) don't support URL parameter pre-filling, but
Markdown templates (.md) do. This adds a structured bug report template that
allows the automated bug reporter to pre-fill all user-submitted data.

Changes:
- Create .github/ISSUE_TEMPLATE/auto_bug_report.md template
- Update bug_report_api.py to use template=auto_bug_report.md parameter
- Update tests to verify template parameter is included in URL
- Add explanatory comments about YAML vs Markdown template differences

Benefits:
- Users see a structured bug report template (not generic issue form)
- All bug report data is pre-filled from the UI form
- Template provides consistent formatting and organization
- Better UX than generic issue creation

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

.github/ISSUE_TEMPLATE/auto_bug_report.md

@@ -0,0 +1,11 @@
+---
+name: Auto Bug Report
+about: Automated bug report from Archon
+title: ''
+labels: bug, auto-report
+assignees: ''
+---
+
+<!-- This template is used for automated bug reports submitted through the Archon UI -->
+<!-- The form data below is automatically filled by the bug reporter -->
+

python/src/server/api_routes/bug_report_api.py

@@ -247,9 +247,10 @@ def _create_manual_submission_response(bug_report: BugReportRequest) -> BugRepor
 
     base_url = f"https://github.com/{github_service.repo}/issues/new"
 
-    # GitHub only supports title and body parameters for pre-filling
-    # Labels cannot be set via URL (requires API or manual selection)
+    # Use Markdown template for structured layout with URL pre-filling support
+    # YAML templates don't support URL parameters, but Markdown templates do
     params = {
+        "template": "auto_bug_report.md",
         "title": bug_report.title,
         "body": issue_body,
     }

python/tests/server/api_routes/test_bug_report_api.py

@@ -119,10 +119,10 @@ def test_manual_submission_url_uses_correct_repo(client, mock_bug_report):
         # Ensure old repository is NOT in URL
         assert "dynamous-community" not in data["issue_url"]
         assert "Archon-V2-Alpha" not in data["issue_url"]
-        # Verify URL contains title and body parameters (not template)
+        # Verify URL contains required parameters including template
         assert "title=" in data["issue_url"]
         assert "body=" in data["issue_url"]
-        assert "template=" not in data["issue_url"]
+        assert "template=auto_bug_report.md" in data["issue_url"]
 
 
 def test_api_submission_with_token(client, mock_bug_report):