fix(installer): make engram stop script exit 0 on clean Windows install

[hansell82]

Summary

On a clean Windows install (no engram process running), gentle-ai install
aborts before configuring any agent:

Error: execute install pipeline: download engram binary:
stop running engram processes before upgrade:
powershell Stop-Process engram: exit status 1 (output: )

Because engram is auto-added as a dependency of every agent install, this
blocks the installer entirely on Windows — even --components skills pulls it in.

Root cause

engramStopScript() (in internal/components/engram/download.go) begins with:

$procs = Get-Process -Name engram -ErrorAction SilentlyContinue
if ($procs) { ... }

On Windows PowerShell 5.1, when no process matches, the suppressed error
still sets $? to $false. The if ($procs) guard is skipped and does not
reset $?, so the script's final automatic status is failure and
powershell.exe -NoProfile -NonInteractive -Command <script> exits 1 with empty
output. stopEngramProcesses() treats any non-zero exit as fatal and aborts the
whole pipeline.

This is the same clean-install regression class as #815 / #919. Those fixes added
the if ($procs) pipeline guard, but the trailing exit code still leaks on a
clean no-op.

Minimal reproduction (Windows PowerShell 5.1)

powershell.exe -NoProfile -NonInteractive -Command '$procs = Get-Process -Name engram -ErrorAction SilentlyContinue; if ($procs) { $procs | Stop-Process -Force -ErrorAction SilentlyContinue }'
echo $LASTEXITCODE   # => 1  (no engram running)

Fix

Append exit 0 to the script. The stop step is best-effort — every call already
uses -ErrorAction SilentlyContinue, and the WARNING: surfacing path (parsed
from stdout by stopEngramProcesses) is unchanged — so forcing a success exit on
a clean no-op is correct.

powershell.exe -NoProfile -NonInteractive -Command '$procs = Get-Process -Name engram -ErrorAction SilentlyContinue; if ($procs) { $procs | Stop-Process -Force -ErrorAction SilentlyContinue }; exit 0'
echo $LASTEXITCODE   # => 0

Verification

Built from this branch on Windows 11 / PowerShell 5.1 and ran
gentle-ai install --agents claude-code --scope global — install now completes
with 65/65 verification checks passing (engram, gga, SDD, skills, theme).

🤖 Generated with Claude Code

Summary by CodeRabbit

• Bug Fixes
  • Improved stop script reliability by ensuring successful completion with proper exit code handling.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Repository UI

Review profile: ASSERTIVE

Plan: Pro Plus

Run ID: 427f2783-029f-4bdf-94ee-461f7333aa6f

📥 Commits

Reviewing files that changed from the base of the PR and between 0a9ffdd and aa41ac6.

📒 Files selected for processing (1)

• internal/components/engram/download.go

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📝 Walkthrough

Walkthrough

engramStopScript() in internal/components/engram/download.go is updated to append an explicit exit 0 line to the generated PowerShell stop script, ensuring the script exits with a success status code after attempting to stop any running engram processes.

Changes

engram PowerShell stop script exit code

Layer / File(s)	Summary
Append exit 0 to stop script internal/components/engram/download.go	Adds exit 0 to the end of the PowerShell script returned by engramStopScript(), so the script always reports a success exit code to its caller after executing the stop logic.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~2 minutes

Possibly related issues

• Install fails agent opencode, claude-code and engram. No Node prereq check. #850: The exit 0 addition directly addresses the reported failure where the PowerShell stop process command was exiting with status 1 during engram installation on Windows.

Possibly related PRs

• Gentleman-Programming/gentle-ai#807: Introduced the Windows stop-before-replace step in engramStopScript(); this PR fixes the exit code produced by that same script.
• Gentleman-Programming/gentle-ai#866: Also modifies the engram stop logic in download.go to prevent the PowerShell stop phase from failing the upgrade flow.
• Gentleman-Programming/gentle-ai#884: Refactored engramStopScript() content and structure, directly related to the helper function modified in this PR.

Suggested labels

type:bug, size:exception

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely describes the main fix: making the engram stop script exit with code 0 on clean Windows installations.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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