feat(web): align the model catalog with the pi-ai provider form

Both editors live in `ui-models` and list the same thing, so they now share
one row shape rather than diverging when #1368 lands: a bordered entry per
model, id and display name on the row, and the capacities behind the row's
own disclosure. The context window is joined there by the per-model output
cap the adapter just gained; both read a decimal K/M suffix.

The shared class names carry this file's token spellings, not that branch's.
`--dsw-alias-border-subtle`, `--dsw-alias-text-tertiary`, and
`--dsw-alias-text-primary` are undeclared, so they resolve to the light-mode
literals in their fallback slots — the defect this section was moved off. A
styles test now rejects any `--dsw-*` name the token sheet does not declare,
so the next editor to name one fails instead of shipping a light-only
surface.

The keystroke buffer is now per capacity field rather than per row, since a
row holds two of them.

apps/web/tests/snapshots/onboarding-deepseek-config/models.expected.md

@@ -32,26 +32,34 @@
         - region "模型目录":
           - text: 模型目录 已自定义模型目录
           - button "恢复默认模型"
-          - textbox "模型 ID 1": deepseek-v4-pro
+          - textbox "模型 ID 1":
+            - /placeholder: 模型 ID
+            - text: deepseek-v4-pro
           - textbox "显示名称 1":
-            - /placeholder: 留空时使用模型 ID
+            - /placeholder: 显示名称
             - text: DeepSeek-V4-Pro
-          - textbox "上下文窗口 1":
-            - /placeholder: 1M
-            - text: 1M
-          - button "删除模型":
+          - button "容量 1":
             - img
-            - text: 删除模型
-          - textbox "模型 ID 2": private-preview
+          - button "删除模型 1":
+            - img
+          - textbox "模型 ID 2":
+            - /placeholder: 模型 ID
+            - text: private-preview
           - textbox "显示名称 2":
-            - /placeholder: 留空时使用模型 ID
+            - /placeholder: 显示名称
             - text: Private Preview
+          - button "容量 2" [expanded]:
+            - img
+          - button "删除模型 2":
+            - img
+          - text: 上下文窗口
           - textbox "上下文窗口 2":
             - /placeholder: 1M
             - text: "131072"
-          - button "删除模型":
-            - img
-            - text: 删除模型
+          - text: 最大输出 token 数
+          - textbox "最大输出 token 数 2":
+            - /placeholder: 256K
+            - text: 64K
           - button "添加模型":
             - img
             - text: 添加模型