MAESTRO: fix(hooks): add session-complete handler to enable orphan reaper cleanup

Cherry-picked from PR #844 by @thusdigital. Sessions stayed in active
sessions map forever after summarize, causing the orphan reaper to think
all processes were still active. Adds session-complete as Stop phase 2
hook that calls POST /api/sessions/complete to remove sessions from the
active map, allowing the reaper to correctly identify and clean up
orphaned worker processes. Fixes #842.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

plugin/hooks/hooks.json

@@ -80,6 +80,11 @@
             "type": "command",
             "command": "node \"${CLAUDE_PLUGIN_ROOT}/scripts/bun-runner.js\" \"${CLAUDE_PLUGIN_ROOT}/scripts/worker-service.cjs\" hook claude-code summarize",
             "timeout": 120
+          },
+          {
+            "type": "command",
+            "command": "node \"${CLAUDE_PLUGIN_ROOT}/scripts/bun-runner.js\" \"${CLAUDE_PLUGIN_ROOT}/scripts/worker-service.cjs\" hook claude-code session-complete",
+            "timeout": 30
           }
         ]
       }