feat: rename to gitea-mcp-extended and add package publishing workflows

Rename the fork from gitea-mcp to gitea-mcp-extended to reflect the
significantly expanded tool coverage (299 vs upstream's 93 tools).

- Rename Go module path and all import references
- Rename binary to gitea-mcp-extended in Makefile, Dockerfile, .gitignore
- Point .goreleaser.yaml gitea_urls to git.lethalbits.com
- Replace release-tag workflow with goreleaser + Generic Package Registry publishing
- Replace release-nightly workflow with cross-platform build + nightly package publishing
- Update CLAUDE.md project description and tool count

CLAUDE.md

@@ -4,7 +4,7 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 
 ## Development Commands
 
-**Build**: `make build` - Build the gitea-mcp binary
+**Build**: `make build` - Build the gitea-mcp-extended binary
 **Install**: `make install` - Build and install to GOPATH/bin
 **Clean**: `make clean` - Remove build artifacts
 **Test**: `go test ./...` - Run all tests
@@ -13,7 +13,7 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 
 ## Architecture Overview
 
-This is a **Gitea MCP (Model Context Protocol) Server** written in Go that provides MCP tools for interacting with Gitea repositories, issues, pull requests, users, and more.
+This is **gitea-mcp-extended**, a Gitea MCP (Model Context Protocol) Server written in Go that provides 299+ MCP tools for interacting with Gitea repositories, issues, pull requests, users, and more. It is a fork of [gitea/gitea-mcp](https://gitea.com/gitea/gitea-mcp) with significantly expanded tool coverage.
 
 **Core Components**:
 
@@ -43,11 +43,11 @@ This is a **Gitea MCP (Model Context Protocol) Server** written in Go that provi
 
 - Default Gitea host: `https://gitea.com` (override with `--host` or `GITEA_HOST`)
 - Environment variables can override CLI flags: `MCP_MODE`, `GITEA_READONLY`, `GITEA_DEBUG`, `GITEA_INSECURE`
-- Logs are written to `~/.gitea-mcp/gitea-mcp.log` with rotation
+- Logs are written to `~/.gitea-mcp/gitea-mcp.log` with rotation (log dir unchanged for backward compatibility)
 
 ## Available Tools
 
-The server provides 40+ MCP tools covering:
+The server provides 299+ MCP tools covering:
 
 - **User**: get_my_user_info, get_user_orgs, search_users
 - **Repository**: create_repo, fork_repo, list_my_repos, search_repos