refactor: apply minimal tfcode branding

- Rename packages/opencode → packages/tfcode (directory only)
- Rename bin/opencode → bin/tfcode (CLI binary)
- Rename .opencode → .tfcode (config directory)
- Update package.json name and bin field
- Update config directory path references (.tfcode)
- Keep internal code references as 'opencode' for easy upstream sync
- Keep @opencode-ai/* workspace package names

This minimal branding approach allows clean merges from upstream
opencode repository while providing tfcode branding for users.

.tfcode/glossary/zh-tw.md

@@ -0,0 +1,42 @@
+# zh-tw Glossary
+
+## Sources
+
+- PR #13942: https://github.com/anomalyco/opencode/pull/13942
+
+## Do Not Translate (Locale Additions)
+
+- `OpenCode` (preserve casing in prose; keep `opencode` only when it is part of commands, package names, paths, or code)
+- `OpenCode Zen`
+- `OpenCode CLI`
+- `CLI`, `TUI`, `MCP`, `OAuth`
+- `Model Context Protocol` (prefer the English expansion when introducing `MCP`)
+
+## Preferred Terms
+
+These are preferred terms for docs/UI prose and may evolve.
+
+| English                 | Preferred | Notes                                       |
+| ----------------------- | --------- | ------------------------------------------- |
+| prompt                  | 提示詞    | Keep `--prompt` unchanged in flags/code     |
+| session                 | 工作階段  |                                             |
+| provider                | 供應商    |                                             |
+| share link / shared URL | 分享連結  | Prefer `分享` for user-facing share actions |
+| headless (server)       | 無介面    | Docs wording                                |
+| authentication          | 認證      | Prefer in auth/OAuth contexts               |
+| cache                   | 快取      |                                             |
+| keybind / shortcut      | 快捷鍵    | User-facing docs wording                    |
+| workflow                | 工作流程  | e.g. GitHub Actions workflow                |
+
+## Guidance
+
+- Prefer natural, concise phrasing over literal translation
+- Keep the tone direct and friendly (PR #13942 consistently moved wording in this direction)
+- Preserve technical artifacts exactly: commands, flags, code, inline code, URLs, file paths, model IDs
+- Keep enum-like values in English when they are literals (for example, `default`, `json`)
+- Prefer consistent terminology across pages once a term is chosen (`工作階段`, `供應商`, `提示詞`, etc.)
+
+## Avoid
+
+- Avoid `opencode` in prose when referring to the product name; use `OpenCode`
+- Avoid mixing alternative terms for the same concept across docs when a preferred term is already established