feat(lease): add single-turn Claude promotion trigger

packages/mosaic/framework/runtime/claude/commands/mosaic-promote.md

@@ -0,0 +1 @@
+I invoked this registered command to authorize lease promotion; follow the local seat broker's injected receipt confirmation instruction exactly.

packages/mosaic/framework/runtime/claude/settings.json

@@ -32,6 +32,18 @@
         ]
       }
     ],
+    "UserPromptSubmit": [
+      {
+        "matcher": "^/mosaic-promote$",
+        "hooks": [
+          {
+            "type": "command",
+            "command": "python3 ~/.config/mosaic/tools/lease-broker/promote-begin.py",
+            "timeout": 15
+          }
+        ]
+      }
+    ],
     "PreToolUse": [
       {
         "matcher": ".*",
@@ -81,8 +93,8 @@
         "hooks": [
           {
             "type": "command",
-            "command": "python3 ~/.config/mosaic/tools/lease-broker/receipt-observer-client.py --runtime claude --latest-entry",
-            "timeout": 3
+            "command": "python3 ~/.config/mosaic/tools/lease-broker/receipt-observer-client.py --runtime claude --latest-entry; observer_status=$?; python3 ~/.config/mosaic/tools/lease-broker/promote-complete.py; exit $observer_status",
+            "timeout": 15
           },
           {
             "type": "command",