fix: keep issue numbers out of model-read Copilot text; seed the new routing sentence in the autoplan fixture

hosts/copilot.ts

@@ -3,7 +3,8 @@ import { defineHost, GBRAIN_RESOLVERS, preambleToolGlossary } from './define-hos
 // GitHub Copilot CLI (#393). Ported from PR #2323 (@andrey-esipov) with ideas
 // from #396/#487 (@ridermw) and #1852 (@lolisaigao1234); disposition in
 // docs/ADDING_A_HOST.md "GitHub Copilot CLI".
-const COPILOT_TOOL_GLOSSARY = '**GitHub Copilot tool names:** `AskUserQuestion` means your `ask_user` tool (one question per call: put the decision brief in the question and each option in the choices). `ExitPlanMode` means `exit_plan_mode`; the Agent tool means `task`; the Read tool means `view`; the Skill tool means `skill`. Copilot has no `mcp__*__AskUserQuestion` variant. **On Windows (#3047):** run each bash block in Git for Windows Bash by its full path (usually `C:\\Program Files\\Git\\bin\\bash.exe`; bare `bash` can start WSL instead). Never translate a block into PowerShell, and never run an extensionless gstack helper from PowerShell directly: Windows opens an app picker instead of running it.';
+// On Windows: Git Bash note (#3047).
+const COPILOT_TOOL_GLOSSARY = '**GitHub Copilot tool names:** `AskUserQuestion` means your `ask_user` tool (one question per call: put the decision brief in the question and each option in the choices). `ExitPlanMode` means `exit_plan_mode`; the Agent tool means `task`; the Read tool means `view`; the Skill tool means `skill`. Copilot has no `mcp__*__AskUserQuestion` variant. **On Windows:** run each bash block in Git for Windows Bash by its full path (usually `C:\\Program Files\\Git\\bin\\bash.exe`; bare `bash` can start WSL instead). Never translate a block into PowerShell, and never run an extensionless gstack helper from PowerShell directly: Windows opens an app picker instead of running it.';
 
 const copilot = defineHost({
   name: 'copilot',

test/helpers/autoplan-preconfigured-fixture.ts

@@ -4,7 +4,7 @@ import { join } from 'node:path';
 // Real project routing, matching the section offered by gstack-skill-start.
 const ROUTING = `## Skill routing
 
-When the user's request matches an available skill, invoke it via the Skill tool. When in doubt, invoke the skill.
+When the user's request matches an available skill, invoke it via the Skill tool. Route only to skills in the session's available-skills list; answer directly for quick questions or small scoped edits.
 
 Key routing rules:
 - Product ideas/brainstorming → invoke /office-hours