Consolidate tools from 110 to 45 using method dispatch (#143)

Consolidate 110 individual MCP tools down to 45 using a method dispatch pattern, aligning tool names with the GitHub MCP server conventions.

**Motivation:** LLMs work better with fewer, well-organized tools. The method dispatch pattern (used by GitHub's MCP server) groups related operations under read/write tools with a `method` parameter.

**Changes:**
- Group related tools into `_read`/`_write` pairs with method dispatch (e.g. `issue_read`, `issue_write`, `pull_request_read`, `pull_request_write`)
- Rename tools to match GitHub MCP naming (`get_file_contents`, `create_or_update_file`, `list_issues`, `list_pull_requests`, etc.)
- Rename `pageSize` to `perPage` for GitHub MCP compat
- Move issue label ops (`add_labels`, `remove_label`, etc.) into `issue_write`
- Merge `create_file`/`update_file` into `create_or_update_file` with optional `sha`
- Make `delete_file` require `sha`
- Add `get_labels` method to `issue_read`
- Add shared helpers: `GetInt64Slice`, `GetStringSlice`, `GetPagination` in params package
- Unexport all dispatch handler functions
- Fix: pass assignees/milestone in `CreateIssue`, bounds check in `GetFileContent`

Reviewed-on: https://gitea.com/gitea/gitea-mcp/pulls/143
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: silverwind <me@silverwind.io>
Co-committed-by: silverwind <me@silverwind.io>

operation/repo/repo.go

@@ -53,7 +53,7 @@ var (
 		ListMyReposToolName,
 		mcp.WithDescription("List my repositories"),
 		mcp.WithNumber("page", mcp.Required(), mcp.Description("Page number"), mcp.DefaultNumber(1), mcp.Min(1)),
-		mcp.WithNumber("pageSize", mcp.Required(), mcp.Description("Page size number"), mcp.DefaultNumber(30), mcp.Min(1)),
+		mcp.WithNumber("perPage", mcp.Required(), mcp.Description("results per page"), mcp.DefaultNumber(30), mcp.Min(1)),
 	)
 )
 
@@ -72,39 +72,6 @@ func init() {
 	})
 }
 
-func RegisterTool(s *server.MCPServer) {
-	s.AddTool(CreateRepoTool, CreateRepoFn)
-	s.AddTool(ForkRepoTool, ForkRepoFn)
-	s.AddTool(ListMyReposTool, ListMyReposFn)
-
-	// File
-	s.AddTool(GetFileContentTool, GetFileContentFn)
-	s.AddTool(CreateFileTool, CreateFileFn)
-	s.AddTool(UpdateFileTool, UpdateFileFn)
-	s.AddTool(DeleteFileTool, DeleteFileFn)
-
-	// Branch
-	s.AddTool(CreateBranchTool, CreateBranchFn)
-	s.AddTool(DeleteBranchTool, DeleteBranchFn)
-	s.AddTool(ListBranchesTool, ListBranchesFn)
-
-	// Release
-	s.AddTool(CreateReleaseTool, CreateReleaseFn)
-	s.AddTool(DeleteReleaseTool, DeleteReleaseFn)
-	s.AddTool(GetReleaseTool, GetReleaseFn)
-	s.AddTool(GetLatestReleaseTool, GetLatestReleaseFn)
-	s.AddTool(ListReleasesTool, ListReleasesFn)
-
-	// Tag
-	s.AddTool(CreateTagTool, CreateTagFn)
-	s.AddTool(DeleteTagTool, DeleteTagFn)
-	s.AddTool(GetTagTool, GetTagFn)
-	s.AddTool(ListTagsTool, ListTagsFn)
-
-	// Commit
-	s.AddTool(ListRepoCommitsTool, ListRepoCommitsFn)
-}
-
 func CreateRepoFn(ctx context.Context, req mcp.CallToolRequest) (*mcp.CallToolResult, error) {
 	log.Debugf("Called CreateRepoFn")
 	args := req.GetArguments()