Remove legacy CI workflows and templates

.gitea/ISSUE_TEMPLATE/proposal.md

@@ -1,41 +0,0 @@
-<!-- Title: Proposal / Design RFC -->
-# Proposal: [Short title]
-
-## Summary
-Concise description of the proposal and what outcome you want.
-
-## Problem statement
-What problem are we solving and why is it important? Include links to related issues.
-
-## Goals
-- Primary goals (what success looks like)
-- Non-goals (explicitly out of scope)
-
-## Proposed design
-Describe the design in detail. Include:
-- Architecture diagrams or ASCII art
-- API changes (requests/responses)
-- Data model changes or migrations
-- UX flows or wireframes
-
-## Alternatives considered
-Short list of alternatives and tradeoffs.
-
-## Backwards compatibility & migration plan
-Describe how to migrate existing data and any compatibility impacts.
-
-## Security considerations
-List potential security/privacy implications.
-
-## Testing & rollout plan
-How will this be tested? Phased rollout plan if needed.
-
-## Implementation plan & timeline
-High-level tasks and owners.
-
-## Open questions
-List any unresolved questions.
-
-**Checklist**
-- [ ] Linked related issues
-- [ ] Prototype or PoC (if available)