## Motivation
Fixes#1456. Models like DeepSeek V3.2, Qwen3, and GLM-4.7 always run in
thinking mode because their chat templates auto-inject `<think>`. Users
need a way to disable thinking for models that support both modes.
## Changes
**API**: Added `enable_thinking: bool | None` to `ChatCompletionRequest`
and `TextGenerationTaskParams`. Passed through the adapter to
`tokenizer.apply_chat_template()` as a kwarg (only when explicitly set,
so models without the template variable are unaffected).
**Dashboard**: Added a thinking toggle button in the chat input area.
Visible only when the selected model has both "text" and "thinking"
capabilities.
## Why It Works
Most thinking model chat templates (DeepSeek, Qwen3, GLM) accept
`enable_thinking` as a Jinja template variable. Passing
`enable_thinking=False` prevents the template from injecting `<think>`,
matching the vLLM convention.
## Test Plan
### Manual Testing
- `curl` with `"enable_thinking": false` against a thinking model — no
`<think>` in output
- Dashboard toggle visible for thinking models, hidden for text-only
models
### Automated Testing
- basedpyright: 0 errors
- ruff: clean
- pytest: 188 passed
- dashboard build: success
---------
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
Alex Cheema
d0c44273db
