docs(skill): list all Theme tokens, warn about hallucinated ones (#287)

* docs(skill): list all Theme tokens, warn about hallucinated ones

Agents consistently hallucinate Theme.Error, Theme.Success, and
Theme.ErrorText which don't exist. Add complete token table with
categories and explicit warning about non-existent tokens.

Fixes #277

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* refactor: move token table to reactor-design skill

Keep the nonexistent-token warning in getting-started as a
critical gotcha, but move the full token table to the design
skill where it belongs alongside the existing token reference.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: sundaramramaswamy

plugins/reactor/skills/reactor-design/SKILL.md

@@ -54,6 +54,9 @@ Hardcoded colors are acceptable only for:
 
 #### Theme Token Reference
 
+> ⚠️ **`Theme.Error`, `Theme.Success`, `Theme.Warning`, `Theme.ErrorText` do NOT exist.**
+> Use `Theme.SystemCritical` (red/error), `Theme.SystemSuccess` (green), `Theme.SystemCaution` (yellow).
+
 **Text:**
 
 | Token | WinUI Resource | Purpose |

plugins/reactor/skills/reactor-getting-started/SKILL.md

@@ -240,12 +240,17 @@ items.Select(i => Component<Card, CardProps>(new CardProps(i)).WithKey(i.Id)).To
 
 ## Theme tokens (always)
 
-Use `Theme.*` for all themed colors — never hardcoded hex on themed surfaces. The full token list with WinUI keys is in the api index.
+Use `Theme.*` for all themed colors — never hardcoded hex on themed surfaces. The full token list with WinUI keys is in the `reactor-design` skill.
+
+> ⚠️ **`Theme.Error`, `Theme.Success`, `Theme.Warning`, `Theme.ErrorText` do NOT exist.**
+> Use `Theme.SystemCritical` (red/error), `Theme.SystemSuccess` (green), `Theme.SystemCaution` (yellow).
 
 ```csharp
 TextBlock("Hi").Foreground(Theme.PrimaryText)
 Border(child).Background(Theme.CardBackground).WithBorder(Theme.CardStroke, 1)
 Button("Action").Background(Theme.Accent)
+TextBlock("Error!").Foreground(Theme.SystemCritical)       // NOT Theme.Error
+TextBlock("Saved").Foreground(Theme.SystemSuccess)         // NOT Theme.Success
 ```
 
 ## Critical gotchas