Bug: SessionStart hook with "compact" matcher not firing after compaction

[hermesthecat]

Environment

• Droid CLI version: 0.70.0
• OS: macOS (darwin 25.3.0)
• Shell: zsh

Description

According to the hooks reference documentation, the SessionStart event should support a "compact"
matcher that fires after auto or manual compaction:

Matchers:

• startup - Invoked from startup
• resume - Invoked from --resume, --continue, or /resume
• clear - Invoked from /clear
• compact - Invoked from auto or manual compact

However, the SessionStart hook with "matcher": "compact" never fires after compaction.

Configuration

{
	"hooks": {
		"SessionStart": [
           {
             "matcher": "compact",
             "hooks": [
               {
                 "type": "command",
                 "command": "python3 ~/.factory/hooks/compact-reinject.py AGENTS.md",
                 "timeout": 10
               }
             ]
           }
         ]
       }
}

Steps to Reproduce

1. Configure a SessionStart hook with "matcher": "compact" as shown above
2. Start a Droid session and work until auto-compaction triggers (or use /compact)
3. Check session logs for hook execution

Expected Behavior

After compaction, the SessionStart hook with "compact" matcher should fire, and the hook's output should be injected into context.

Actual Behavior
• The compaction_state event appears in session logs
• No SessionStart hook fires after compaction
• No hook output (e.g., additionalContext) is injected

Session log analysis shows:

1. compaction_state entry exists with timestamp
2. Next message after compaction has NO hook output injected
3. The expected [RE-INJECTED AFTER COMPACTION: ...] context never appears