Inline issue/comment attachments in body (#183)

The Gitea API returns an `assets` array on issue and comment responses, but the SDK structs drop it — so attachments are invisible to MCP agents.

Append each attachment as a `[name](url)` markdown link at the end of the body, mirroring how GitHub embeds attachments inline (which `github-mcp-server` preserves as-is).

**Coverage:**
- `issue_read get` — issue body attachments
- `issue_read get_comments` — issue and PR conversation comment attachments (same endpoint)
- `pull_request_read get` — PR description attachments (Gitea's `/pulls/` endpoint omits `assets`, so a follow-up best-effort call to `/issues/{n}/assets` surfaces them; PRs are issues internally)

PR review summaries and line-comment reviews don't support attachments per the Gitea API spec, so nothing to do there.

Closes https://gitea.com/gitea/gitea-mcp/issues/182

---
This PR was written with the help of Claude Opus 4.7

Reviewed-on: https://gitea.com/gitea/gitea-mcp/pulls/183
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: silverwind <me@silverwind.io>
Co-committed-by: silverwind <me@silverwind.io>

operation/pull/pull.go

@@ -3,6 +3,7 @@ package pull
 import (
 	"context"
 	"fmt"
+	"net/url"
 	"strings"
 
 	"gitea.com/gitea/gitea-mcp/pkg/gitea"
@@ -209,7 +210,17 @@ func getPullRequestByIndexFn(ctx context.Context, req mcp.CallToolRequest) (*mcp
 		return to.ErrorResult(fmt.Errorf("get %v/%v/pr/%v err: %v", owner, repo, index, err))
 	}
 
-	return to.TextResult(slimPullRequest(pr))
+	// /pulls/{n} omits `assets`; PRs are issues internally, so the issue
+	// assets endpoint surfaces description attachments.
+	var assets []*gitea_sdk.Attachment
+	assetsPath := fmt.Sprintf("repos/%s/%s/issues/%d/assets", url.PathEscape(owner), url.PathEscape(repo), index)
+	if _, err := gitea.DoJSON(ctx, "GET", assetsPath, nil, nil, &assets); err != nil {
+		log.Debugf("fetch %v/%v/issues/%v/assets err: %v", owner, repo, index, err)
+	}
+
+	m := slimPullRequest(pr)
+	m["body"] = bodyWithAttachments(pr.Body, assets)
+	return to.TextResult(m)
 }
 
 func getPullRequestDiffFn(ctx context.Context, req mcp.CallToolRequest) (*mcp.CallToolResult, error) {