fix(create_project_from_template): accept per-call template_name override

The template name was hardcoded into the binary at startup via
NewCreateProjectFromTemplate("mathias", "template-go-web"), so
generating from a different template (e.g. template-go-agent)
required a code change and restart. The constructor already
parameterised it correctly — the gap was at the tool's input
schema, which never exposed template_name to the caller.

Adds an optional template_name input field. When set, it overrides
the server-configured default for that call only; when omitted,
behavior is unchanged. Template owner stays server-configured —
only the repo name is per-call.

Server-side validation already verifies the resolved template
exists and is marked as a template repo, so no enum constraint
is added — keeps the door open for future templates (go-ml,
go-service, ...) without redeploys.

Adds TestCreateProjectTemplateNameOverride verifying the override
directs both the template lookup and the /generate POST.

Closes #24

internal/tools/create_project_from_template.go

@@ -45,14 +45,15 @@ func NewCreateProjectFromTemplate(c *gitea.Client, a *allowlist.Allowlist, tmplO
 func (t *CreateProjectFromTemplate) Descriptor() registry.ToolDescriptor {
 	return registry.ToolDescriptor{
 		Name:        "create_project_from_template",
-		Description: "Create a new project repo from the template, applying placeholder substitutions to known files.",
+		Description: "Create a new project repo from a template, applying placeholder substitutions to known files. Defaults to the server-configured template; pass template_name to override (e.g. template-go-agent).",
 		InputSchema: json.RawMessage(`{
 			"type":"object",
 			"properties":{
 				"owner":{"type":"string"},
 				"name":{"type":"string","pattern":"^[a-z][a-z0-9-]{1,38}[a-z0-9]$"},
 				"description":{"type":"string"},
-				"private":{"type":"boolean"}
+				"private":{"type":"boolean"},
+				"template_name":{"type":"string","description":"Template repo name to generate from. Defaults to the server-configured template."}
 			},
 			"required":["owner","name"]
 		}`),
@@ -64,6 +65,7 @@ type createProjectArgs struct {
 	Name         string `json:"name"`
 	Description  string `json:"description"`
 	Private      bool   `json:"private"`
+	TemplateName string `json:"template_name"`
 }
 
 type createProjectResult struct {
@@ -91,13 +93,20 @@ func (t *CreateProjectFromTemplate) Call(ctx context.Context, raw json.RawMessag
 		return nil, fmt.Errorf("name %q does not match pattern %s: %w", args.Name, nameRe.String(), gitea.ErrValidation)
 	}
 
+	// Resolve template: per-call override takes precedence over the
+	// server-configured default. Owner stays server-configured.
+	tmplName := args.TemplateName
+	if tmplName == "" {
+		tmplName = t.templateName
+	}
+
 	// Verify template exists and is marked as a template repo.
-	tmpl, err := t.c.GetRepo(ctx, t.templateOwner, t.templateName)
+	tmpl, err := t.c.GetRepo(ctx, t.templateOwner, tmplName)
 	if err != nil {
 		return nil, fmt.Errorf("template lookup: %w", err)
 	}
 	if !tmpl.Template {
-		return nil, fmt.Errorf("repo %s/%s is not marked as template: %w", t.templateOwner, t.templateName, gitea.ErrValidation)
+		return nil, fmt.Errorf("repo %s/%s is not marked as template: %w", t.templateOwner, tmplName, gitea.ErrValidation)
 	}
 
 	// Verify destination doesn't already exist.
@@ -108,7 +117,7 @@ func (t *CreateProjectFromTemplate) Call(ctx context.Context, raw json.RawMessag
 	}
 
 	// Generate repo from template.
-	newRepo, err := t.c.GenerateFromTemplate(ctx, t.templateOwner, t.templateName, gitea.GenerateFromTemplateArgs{
+	newRepo, err := t.c.GenerateFromTemplate(ctx, t.templateOwner, tmplName, gitea.GenerateFromTemplateArgs{
 		Owner:       args.Owner,
 		Name:        args.Name,
 		Description: args.Description,

internal/tools/create_project_from_template_test.go

@@ -122,6 +122,62 @@ func TestCreateProjectHappyPath(t *testing.T) {
 	assert.Empty(t, out.PartialFailure)
 }
 
+// TestCreateProjectTemplateNameOverride (issue #24): per-call template_name overrides the
+// server-configured default, so the same binary can generate from template-go-web or
+// template-go-agent without restart.
+func TestCreateProjectTemplateNameOverride(t *testing.T) {
+	var templateLookups, generateCalls []string
+
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		switch {
+		case r.Method == http.MethodGet && r.URL.Path == "/api/v1/repos/mathias/template-go-agent":
+			templateLookups = append(templateLookups, "template-go-agent")
+			_, _ = w.Write([]byte(newTemplateRepoJSON("template-go-agent", true)))
+
+		case r.Method == http.MethodGet && r.URL.Path == "/api/v1/repos/mathias/template-go-web":
+			templateLookups = append(templateLookups, "template-go-web")
+			_, _ = w.Write([]byte(newTemplateRepoJSON("template-go-web", true)))
+
+		case r.Method == http.MethodGet && r.URL.Path == "/api/v1/repos/mathias/new-agent":
+			w.WriteHeader(http.StatusNotFound)
+			_, _ = w.Write([]byte(`{"message":"not found"}`))
+
+		case r.Method == http.MethodPost && strings.HasSuffix(r.URL.Path, "/generate"):
+			generateCalls = append(generateCalls, r.URL.Path)
+			w.WriteHeader(http.StatusCreated)
+			_, _ = w.Write([]byte(newGeneratedRepoJSON("new-agent")))
+
+		case r.Method == http.MethodGet && strings.HasPrefix(r.URL.Path, "/api/v1/repos/mathias/new-agent/contents/"):
+			filePath := strings.TrimPrefix(r.URL.Path, "/api/v1/repos/mathias/new-agent/contents/")
+			_, _ = w.Write([]byte(fileContentsJSON(filePath)))
+
+		case r.Method == http.MethodPut && strings.HasPrefix(r.URL.Path, "/api/v1/repos/mathias/new-agent/contents/"):
+			filePath := strings.TrimPrefix(r.URL.Path, "/api/v1/repos/mathias/new-agent/contents/")
+			w.WriteHeader(http.StatusOK)
+			_, _ = w.Write([]byte(fileWriteResultJSON(filePath)))
+
+		default:
+			t.Errorf("unexpected request: %s %s", r.Method, r.URL.Path)
+			w.WriteHeader(http.StatusNotFound)
+		}
+	}))
+	defer srv.Close()
+
+	// Server is configured with template-go-web as the default; call overrides to template-go-agent.
+	tool := newCreateProjectTool(srv.URL)
+	_, err := tool.Call(context.Background(), json.RawMessage(
+		`{"owner":"mathias","name":"new-agent","template_name":"template-go-agent"}`,
+	))
+	require.NoError(t, err)
+
+	assert.Equal(t, []string{"template-go-agent"}, templateLookups,
+		"override must direct the template lookup, not the server default")
+	require.Len(t, generateCalls, 1)
+	assert.Equal(t, "/api/v1/repos/mathias/template-go-agent/generate", generateCalls[0],
+		"override must direct the /generate call too")
+}
+
 // TestCreateProjectNameRegexFailure: invalid name returns ErrValidation without hitting network.
 func TestCreateProjectNameRegexFailure(t *testing.T) {
 	tool := tools.NewCreateProjectFromTemplate(