fix: Windows daemon ENOENT, keepalive drain, and headless worker shell resolution

[onurgoz]

Summary

Fixes 3 of 4 bugs reported in #1446 — Windows daemon and headless worker failures:

Bug 1: Daemon ENOENT with spaced paths

spawn(process.execPath, ...) with shell: true on Windows fails when process.execPath contains spaces (e.g. C:\Program Files\nodejs\node.exe) because cmd.exe splits on unquoted spaces.

Fix: Quote process.execPath on Windows before passing to spawn.

Bug 2: Daemon dies in quiet/detached mode

await new Promise(() => {}) alone does not keep the Node.js event loop alive when there's no active I/O handle. The daemon exits within 1-2 seconds.

Fix: Add setInterval(() => {}, 60_000) as an active timer handle before the blocking promise.

Bug 3: Headless workers empty output on Windows

spawn('claude', ...) without shell: true fails on Windows because claude is installed as claude.cmd — Node's spawn doesn't search PATH for .cmd extensions without shell mode.

Fix: Add shell: true to spawn options on Windows.

Changed files

File	Line	Change
v3/@claude-flow/cli/src/commands/daemon.ts	285	Quote process.execPath on Windows
v3/@claude-flow/cli/src/commands/daemon.ts	180	Add setInterval keepalive in quiet mode
v3/@claude-flow/cli/src/services/headless-worker-executor.ts	1146	Add shell: true on Windows

Test plan

• On Windows with Node.js installed in C:\Program Files\: npx ruflo daemon start should succeed
• Daemon should stay alive in --foreground --quiet mode
• Headless workers should produce non-empty output on Windows
• Verify no regression on macOS/Linux (changes are Windows-only)

Ref #1446