feat(tools): issue_get, release_create, repo_delete (#11, #17, #20)

issue_get: GET /repos/{owner}/{repo}/issues/{number} — full issue with labels, assignees, comment count
release_create: POST /repos/{owner}/{repo}/releases — create release and tag in one call
repo_delete: DELETE /repos/{owner}/{repo} — confirm=<repo name> required, blocks accidents

internal/tools/issue_get.go

@@ -0,0 +1,54 @@
+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 IssueGet struct {
+	c *gitea.Client
+	a *allowlist.Allowlist
+}
+
+func NewIssueGet(c *gitea.Client, a *allowlist.Allowlist) *IssueGet { return &IssueGet{c: c, a: a} }
+
+func (t *IssueGet) Descriptor() registry.ToolDescriptor {
+	return registry.ToolDescriptor{
+		Name:        "issue_get",
+		Description: "Get a single issue by number, including body, state, labels, assignees, and comment count.",
+		InputSchema: json.RawMessage(`{
+			"type":"object",
+			"properties":{
+				"owner":{"type":"string"},
+				"name":{"type":"string"},
+				"number":{"type":"integer","minimum":1}
+			},
+			"required":["owner","name","number"]
+		}`),
+	}
+}
+
+type issueGetArgs struct {
+	Owner  string `json:"owner"`
+	Name   string `json:"name"`
+	Number int    `json:"number"`
+}
+
+func (t *IssueGet) Call(ctx context.Context, raw json.RawMessage) (json.RawMessage, error) {
+	var args issueGetArgs
+	if err := parseArgs(raw, &args); err != nil {
+		return nil, err
+	}
+	if err := t.a.Check(args.Owner); err != nil {
+		return nil, err
+	}
+	iss, err := t.c.GetIssue(ctx, args.Owner, args.Name, args.Number)
+	if err != nil {
+		return nil, err
+	}
+	return textOK(iss)
+}