fix(onboard): replace broken preflight check with direct config file test (Fission-AI#637)

The onboarding preflight used `openspec status --json` to detect if a
project was initialized, but that command requires an existing change
to succeed. After a fresh `openspec init` (no changes yet), it always
failed — causing the onboarding to incorrectly tell users to run init
again.

Replace with two targeted checks:
- `openspec --version` to verify the CLI is installed
- `test -f openspec/config.yaml` to verify project initialization

Author: TabishB

.changeset/fix-onboarding-preflight.md

@@ -0,0 +1,5 @@
+---
+"openspec": patch
+---
+
+Fix onboarding preflight check that incorrectly reported freshly initialized projects as not initialized. Replaced `openspec status --json` (which requires an existing change) with a direct `openspec/config.yaml` existence check. Also added an `openspec --version` check to verify the CLI is installed.

src/core/templates/skill-templates.ts

@@ -937,16 +937,23 @@ function getOnboardInstructions(): string {
 
 ## Preflight
 
-Before starting, check if OpenSpec is initialized:
+Before starting, check if the OpenSpec CLI is installed and the project is initialized:
 
 \`\`\`bash
-openspec status --json 2>&1 || echo "NOT_INITIALIZED"
+openspec --version 2>&1 || echo "CLI_NOT_INSTALLED"
 \`\`\`
 
+\`\`\`bash
+test -f openspec/config.yaml && echo "INITIALIZED" || echo "NOT_INITIALIZED"
+\`\`\`
+
+**If CLI not installed:**
+> OpenSpec CLI is not installed. Install it first, then come back to \`/opsx:onboard\`.
+
 **If not initialized:**
 > OpenSpec isn't set up in this project yet. Run \`openspec init\` first, then come back to \`/opsx:onboard\`.
 
-Stop here if not initialized.
+Stop here if either check fails.
 
 ---