feat: add wiki CLI commands (#998)

## Summary

Add first-class `tea wiki` commands backed by the existing Gitea wiki API and SDK support.

## What this adds

- `tea wiki list`
- `tea wiki view <page>`
- `tea wiki revisions <page>`
- `tea wiki create`
- `tea wiki edit <page>`
- `tea wiki delete <page>`

## Implementation details

- registers a new top-level `wiki` entity command
- keeps command logic under `cmd/wiki/`
- adds wiki-specific renderers in `modules/print/wiki.go`
- adds wiki task helpers in `modules/task/wiki.go`
- reuses existing repo/login/output/pagination patterns used elsewhere in `tea`
- base64-encodes wiki content for create/edit API calls
- requires explicit `--confirm` for delete
- preserves the current page title during edit when `--title` is omitted

## Test coverage

The PR is intentionally split into two commits:

1. `feat: add wiki CLI commands`
2. `test: add wiki integration coverage`

Validation performed:

- focused command, task, and print tests for the new wiki functionality
- integration coverage for the wiki command lifecycle
- `make lint`
- `make fmt-check`
- `make docs-check`
- `make build`
- upstream PR CI passed:
  - `check-and-test / Integration Test`
  - `check-and-test / Lint Build And Unit Coverage`

## Motivation

This makes `tea` a better interface for both human and agent-driven workflows by exposing wiki operations as stable first-class CLI commands instead of requiring ad-hoc API calls or custom wrappers.

---
Generated by Hermes Agent with GPT-5.4

---------

Co-authored-by: nitro <nitro@nitroui-Macmini.local>
Reviewed-on: https://gitea.com/gitea/tea/pulls/998
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: kuil09 <202447+kuil09@noreply.gitea.com>
Co-committed-by: kuil09 <202447+kuil09@noreply.gitea.com>

tests/integration/wiki_test.go

@@ -0,0 +1,170 @@
+// Copyright 2026 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package integration
+
+import (
+	"bytes"
+	"context"
+	"encoding/base64"
+	"fmt"
+	"io"
+	"os"
+	"strings"
+	"testing"
+	"time"
+
+	"gitea.dev/sdk"
+	teacmd "gitea.dev/tea/cmd"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestWikiCommandLifecycle(t *testing.T) {
+	login := createIntegrationLogin(t)
+	client := login.Client()
+	repoName := fmt.Sprintf("tea-wiki-integration-%d", time.Now().UnixNano())
+
+	_, _, err := client.CreateRepo(context.Background(), gitea.CreateRepoOption{Name: repoName})
+	require.NoError(t, err)
+	t.Cleanup(func() {
+		if _, delErr := client.DeleteRepo(context.Background(), login.User, repoName); delErr != nil {
+			t.Logf("failed to delete integration test repo %q: %v", repoName, delErr)
+		}
+	})
+
+	repoSlug := fmt.Sprintf("%s/%s", login.User, repoName)
+
+	createOutput := runTeaCommand(t,
+		"wiki", "create",
+		"--login", login.Name,
+		"--repo", repoSlug,
+		"--title", "Home",
+		"--content", "# Home",
+		"--message", "create home",
+		"--output", "json",
+	)
+	assert.Contains(t, createOutput, "\"title\": \"Home\"")
+
+	page, _, err := client.Wiki.GetPage(context.Background(), login.User, repoName, "Home")
+	require.NoError(t, err)
+	assert.Equal(t, "Home", page.Title)
+	assert.Contains(t, decodeBase64String(t, page.ContentBase64), "# Home")
+
+	listOutput := runTeaCommand(t,
+		"wiki", "list",
+		"--login", login.Name,
+		"--repo", repoSlug,
+		"--output", "json",
+	)
+	assert.Contains(t, listOutput, "\"title\": \"Home\"")
+
+	emptyRepoName := fmt.Sprintf("tea-wiki-empty-%d", time.Now().UnixNano())
+	_, _, err = client.CreateRepo(context.Background(), gitea.CreateRepoOption{Name: emptyRepoName})
+	require.NoError(t, err)
+	t.Cleanup(func() {
+		if _, delErr := client.DeleteRepo(context.Background(), login.User, emptyRepoName); delErr != nil {
+			t.Logf("failed to delete empty wiki repo %q: %v", emptyRepoName, delErr)
+		}
+	})
+	emptyRepoSlug := fmt.Sprintf("%s/%s", login.User, emptyRepoName)
+	emptyListOutput := runTeaCommand(t,
+		"wiki", "list",
+		"--login", login.Name,
+		"--repo", emptyRepoSlug,
+	)
+	assert.Contains(t, emptyListOutput, "No wiki pages found")
+
+	viewOutput := runTeaCommand(t,
+		"wiki", "view", "Home",
+		"--login", login.Name,
+		"--repo", repoSlug,
+		"--output", "json",
+	)
+	assert.Contains(t, viewOutput, "\"title\": \"Home\"")
+	assert.Contains(t, viewOutput, "\"content\": \"# Home\"")
+
+	runTeaCommand(t,
+		"wiki", "edit", "Home",
+		"--login", login.Name,
+		"--repo", repoSlug,
+		"--content", "# Updated",
+		"--message", "edit home",
+		"--output", "json",
+	)
+
+	page, _, err = client.Wiki.GetPage(context.Background(), login.User, repoName, "Home")
+	require.NoError(t, err)
+	assert.Equal(t, "Home", page.Title)
+	assert.Contains(t, decodeBase64String(t, page.ContentBase64), "# Updated")
+
+	viewRenderedOutput := runTeaCommand(t,
+		"wiki", "view", "Home",
+		"--login", login.Name,
+		"--repo", repoSlug,
+	)
+	assert.Contains(t, viewRenderedOutput, "# Updated")
+	assert.NotContains(t, viewRenderedOutput, "Last updated")
+
+	revisionsOutput := runTeaCommand(t,
+		"wiki", "revisions", "Home",
+		"--login", login.Name,
+		"--repo", repoSlug,
+		"--output", "json",
+	)
+	assert.Contains(t, revisionsOutput, "create home")
+	assert.Contains(t, revisionsOutput, "edit home")
+
+	runTeaCommand(t,
+		"wiki", "delete", "Home",
+		"--login", login.Name,
+		"--repo", repoSlug,
+		"--confirm",
+	)
+
+	_, _, err = client.Wiki.GetPage(context.Background(), login.User, repoName, "Home")
+	require.Error(t, err)
+	assert.True(t, strings.Contains(strings.ToLower(err.Error()), "not found") || strings.Contains(strings.ToLower(err.Error()), "404"))
+}
+
+func runTeaCommand(t *testing.T, args ...string) string {
+	t.Helper()
+
+	app := teacmd.App()
+	errBuf := &bytes.Buffer{}
+	app.Writer = io.Discard
+	app.ErrWriter = errBuf
+
+	oldStdout := os.Stdout
+	reader, writer, err := os.Pipe()
+	require.NoError(t, err)
+	os.Stdout = writer
+	defer func() {
+		os.Stdout = oldStdout
+	}()
+
+	done := make(chan string, 1)
+	go func() {
+		var outBuf bytes.Buffer
+		_, _ = io.Copy(&outBuf, reader)
+		done <- outBuf.String()
+	}()
+
+	runErr := app.Run(context.Background(), append([]string{"tea"}, args...))
+	require.NoError(t, writer.Close())
+	output := <-done
+	require.NoError(t, reader.Close())
+
+	require.NoError(t, runErr, "tea %s failed with stdout: %s\nstderr: %s", strings.Join(args, " "), output, errBuf.String())
+
+	return output
+}
+
+func decodeBase64String(t *testing.T, encoded string) string {
+	t.Helper()
+
+	decoded, err := base64.StdEncoding.DecodeString(encoded)
+	require.NoError(t, err)
+
+	return string(decoded)
+}