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>

docs/CLI.md

@@ -1657,6 +1657,122 @@ Disable a workflow
 
 **--repo, -r**="": Override local repository path or gitea repository slug to interact with. Optional
 
+## wiki
+
+Manage repository wiki pages
+
+**--fields, -f**="": Comma-separated list of fields to print. Available values:
+			title,path,url,sha,author,updated,message
+		 (default: "title,author,updated,sha")
+
+**--limit, --lm**="": specify limit of items per page (default: 30)
+
+**--login, -l**="": Use a different Gitea Login. Optional
+
+**--output, -o**="": Output format. (simple, table, csv, tsv, yaml, json)
+
+**--page, -p**="": specify page (default: 1)
+
+**--remote, -R**="": Discover Gitea login from remote. Optional
+
+**--repo, -r**="": Override local repository path or gitea repository slug to interact with. Optional
+
+### list, ls
+
+List wiki pages of the repository
+
+**--fields, -f**="": Comma-separated list of fields to print. Available values:
+			title,path,url,sha,author,updated,message
+		 (default: "title,author,updated,sha")
+
+**--limit, --lm**="": specify limit of items per page (default: 30)
+
+**--login, -l**="": Use a different Gitea Login. Optional
+
+**--output, -o**="": Output format. (simple, table, csv, tsv, yaml, json)
+
+**--page, -p**="": specify page (default: 1)
+
+**--remote, -R**="": Discover Gitea login from remote. Optional
+
+**--repo, -r**="": Override local repository path or gitea repository slug to interact with. Optional
+
+### view
+
+View a wiki page
+
+**--login, -l**="": Use a different Gitea Login. Optional
+
+**--output, -o**="": Output format. (simple, table, csv, tsv, yaml, json)
+
+**--remote, -R**="": Discover Gitea login from remote. Optional
+
+**--repo, -r**="": Override local repository path or gitea repository slug to interact with. Optional
+
+### revisions, history
+
+List revisions of a wiki page
+
+**--fields, -f**="": Comma-separated list of fields to print. Available values:
+			sha,message,author,date
+		 (default: "sha,author,date,message")
+
+**--limit, --lm**="": specify limit of items per page (default: 30)
+
+**--login, -l**="": Use a different Gitea Login. Optional
+
+**--output, -o**="": Output format. (simple, table, csv, tsv, yaml, json)
+
+**--page, -p**="": specify page (default: 1)
+
+**--remote, -R**="": Discover Gitea login from remote. Optional
+
+**--repo, -r**="": Override local repository path or gitea repository slug to interact with. Optional
+
+### create, c
+
+Create a wiki page
+
+**--content, -c**="": wiki page content
+
+**--login, -l**="": Use a different Gitea Login. Optional
+
+**--message, -m**="": commit message for the wiki change
+
+**--remote, -R**="": Discover Gitea login from remote. Optional
+
+**--repo, -r**="": Override local repository path or gitea repository slug to interact with. Optional
+
+**--title, -t**="": wiki page title
+
+### edit, e
+
+Edit a wiki page
+
+**--content, -c**="": wiki page content
+
+**--login, -l**="": Use a different Gitea Login. Optional
+
+**--message, -m**="": commit message for the wiki change
+
+**--remote, -R**="": Discover Gitea login from remote. Optional
+
+**--repo, -r**="": Override local repository path or gitea repository slug to interact with. Optional
+
+**--title, -t**="": wiki page title
+
+### delete, rm
+
+Delete a wiki page
+
+**--confirm, -y**: confirm deletion without prompting
+
+**--login, -l**="": Use a different Gitea Login. Optional
+
+**--remote, -R**="": Discover Gitea login from remote. Optional
+
+**--repo, -r**="": Override local repository path or gitea repository slug to interact with. Optional
+
 ## webhooks, webhook, hooks, hook
 
 Manage webhooks