docs(kb): migrate Gitea documentation to KB system

Migrated all Gitea documentation from docs/GITEA/ folder into the Knowledge
Base system, following KB naming conventions and frontmatter requirements.

## What Was Migrated

### Gitea Documentation Guides (6 KB entries)

1. **Gitea Basics Guide** ()
   - Core concepts and features of Gitea
   - Key differences from GitHub
   - Terminology and common workflows
   - System requirements

2. **Gitea Actions Guide** ()
   - Gitea Actions CI/CD system
   - Compatibility with GitHub Actions
   - Workflow creation and patterns
   - Troubleshooting guide

3. **LLM Guidelines for Gitea** ()
   - Terminology guidelines for LLMs
   - Documentation standards
   - Common scenarios and checklist
   - Quick reference

4. **Gitea Workflows Guide** ()
   - Common workflows (repository setup, branches, PRs, issues)
   - Best practices (branch naming, commits, PR process)
   - Integration with documentation systems
   - Troubleshooting

5. **Gitea API Reference** ()
   - API authentication and endpoints
   - Differences from GitHub API
   - Common use cases
   - MCP server integration

6. **Gitea Documentation Overview** ()
   - Overview and index of all Gitea documentation
   - Quick reference guide
   - Links to all Gitea KB entries

## KB System Compliance

✅ All files follow KB naming convention (YYYY-MM-DD--slug--type.md)
✅ All files have complete frontmatter (all 18 required fields)
✅ All files categorized in 02_systems/ (infrastructure/tooling)
✅ All files reference original documentation location
✅ KB changelog updated with migration entry
✅ KB index regenerated via script (8 files, 23 topics, 31 tags)

## Category Decision

All Gitea documentation entries were placed in **02_systems/** category
because:
- Gitea is infrastructure/tooling (not project-specific)
- Documentation covers platform usage and integration
- Guides are system-level references
- Fits KB category definition: "Infrastructure, DevOps, tooling"

## Original Documentation

Original documentation remains in  folder:
- docs/GITEA/Gitea-Basics.md
- docs/GITEA/Gitea-Actions-Guide.md
- docs/GITEA/LLM-Gitea-Guidelines.md
- docs/GITEA/Gitea-Workflows.md
- docs/GITEA/Gitea-API-Reference.md
- docs/GITEA/README.md

KB entries reference original locations for full documentation.

## Benefits

- Gitea documentation now searchable via KB index
- Integrated with KB system for LLM discovery
- Consistent with other KB entries
- Maintains reference to original documentation
- Provides comprehensive Gitea platform reference

kb/CHANGELOG.md

@@ -2,6 +2,24 @@
 
 All notable changes to KB files and system.
 
+## [2025-11-11] Gitea Documentation Migration
+
+### Added
+- `kb/02_systems/2025-11-11--gitea-basics-guide--howto.md` - Gitea platform basics guide
+- `kb/02_systems/2025-11-11--gitea-actions-guide--howto.md` - Gitea Actions CI/CD guide
+- `kb/02_systems/2025-11-11--gitea-llm-guidelines--howto.md` - LLM guidelines for Gitea
+- `kb/02_systems/2025-11-11--gitea-workflows-guide--howto.md` - Gitea workflows and best practices
+- `kb/02_systems/2025-11-11--gitea-api-reference--howto.md` - Gitea API reference guide
+- `kb/02_systems/2025-11-11--gitea-documentation-overview--note.md` - Gitea documentation overview and index
+
+### Notes
+- Migrated all Gitea documentation from `docs/GITEA/` to KB system
+- All entries categorized in `02_systems/` (infrastructure/tooling)
+- Entries reference original documentation location
+- Provides comprehensive Gitea platform reference for LLMs and developers
+
+---
+
 ## [2025-11-11] Issues Capture System Documentation
 
 ### Added