feat(tools): repo_tree, repo_topics_update, file_read dir fix (#14, #15, #18)

repo_tree: GET /git/trees/{ref}?recursive=1 — full recursive file tree
repo_topics_update: PUT /repos/{owner}/{repo}/topics — replace topic list
file_read: detect array response and return descriptive error for dir paths

internal/tools/repo_topics_update.go

@@ -0,0 +1,55 @@
+package tools
+
+import (
+	"context"
+	"encoding/json"
+
+	"gitea.d-ma.be/mathias/gitea-mcp/internal/allowlist"
+	"gitea.d-ma.be/mathias/gitea-mcp/internal/gitea"
+	"gitea.d-ma.be/mathias/gitea-mcp/internal/registry"
+)
+
+type RepoTopicsUpdate struct {
+	c *gitea.Client
+	a *allowlist.Allowlist
+}
+
+func NewRepoTopicsUpdate(c *gitea.Client, a *allowlist.Allowlist) *RepoTopicsUpdate {
+	return &RepoTopicsUpdate{c: c, a: a}
+}
+
+func (t *RepoTopicsUpdate) Descriptor() registry.ToolDescriptor {
+	return registry.ToolDescriptor{
+		Name:        "repo_topics_update",
+		Description: "Replace the topic list for a repository.",
+		InputSchema: json.RawMessage(`{
+			"type":"object",
+			"properties":{
+				"owner":{"type":"string"},
+				"name":{"type":"string"},
+				"topics":{"type":"array","items":{"type":"string"},"description":"Full replacement list. Send [] to clear all topics."}
+			},
+			"required":["owner","name","topics"]
+		}`),
+	}
+}
+
+type repoTopicsUpdateArgs struct {
+	Owner  string   `json:"owner"`
+	Name   string   `json:"name"`
+	Topics []string `json:"topics"`
+}
+
+func (t *RepoTopicsUpdate) Call(ctx context.Context, raw json.RawMessage) (json.RawMessage, error) {
+	var args repoTopicsUpdateArgs
+	if err := parseArgs(raw, &args); err != nil {
+		return nil, err
+	}
+	if err := t.a.Check(args.Owner); err != nil {
+		return nil, err
+	}
+	if err := t.c.UpdateTopics(ctx, args.Owner, args.Name, args.Topics); err != nil {
+		return nil, err
+	}
+	return textOK(map[string]any{"status": "updated", "topics": args.Topics})
+}