Fix Linux compatibility: Replace hardcoded macOS paths in Observability

[christauff]

Problem

PAI v2.4's Observability dashboard fails on Linux systems due to hardcoded macOS path encoding.

Both task-watcher.ts and file-ingest.ts use -Users- prefix which only works for macOS paths like /Users/username. Linux systems use /home/username, causing the dashboard to show empty even when agents are running.

Solution

Replace hardcoded path construction with dynamic HOME environment variable encoding:

// Before (macOS only)
const TASKS_DIR = \`/tmp/claude/-Users-\${process.env.USER}--claude/tasks\`;

// After (cross-platform)
const homePathEncoded = (process.env.HOME || homedir()).replace(/\//g, '-');
const TASKS_DIR = \`/tmp/claude/\${homePathEncoded}--claude/tasks\`;

Impact

• Remote tab: Now displays background task timeline on Linux
• Local tab: Now displays PAI hook events on Linux
• Backward compatible: macOS paths unchanged

Testing

Tested on:

• ✅ Ubuntu 24.04 (Linux 6.14.0-37-generic)
• ✅ Confirmed both dashboard tabs functional

Files Changed

• `Packs/pai-observability-server/src/Observability/apps/server/src/task-watcher.ts`
• `Packs/pai-observability-server/src/Observability/apps/server/src/file-ingest.ts`

[realGregorVucajnk]

Nice, thank you!