Replace Python CLI with Gitea issue tracker setup

Switch from a custom CLI ticketing tool to Gitea-native issue tracking.
Add issue templates (bug, feature, task) and a curated initial backlog
of 20 tickets covering project foundation, testing, security, docs,
features, and community maintenance.

.gitea/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,36 @@
+---
+name: "🐛 Bug Report"
+about: "Report something that is broken or not working as expected."
+title: "[Bug] "
+labels: ["bug", "triage"]
+assignees: []
+---
+
+## Description
+
+<!-- A clear, concise description of the bug. -->
+
+## Steps to Reproduce
+
+1.
+2.
+3.
+
+## Expected Behavior
+
+<!-- What did you expect to happen? -->
+
+## Actual Behavior
+
+<!-- What actually happened? Include logs or screenshots if helpful. -->
+
+## Environment
+
+- **OS / Distro:**
+- **Browser / Runtime version:**
+- **Commit / Release:** <!-- e.g. main @ a1b2c3d -->
+
+## Additional Context
+
+<!-- Any other details that might help diagnose the issue. -->
+